A series of consolidated undrained triaxial tests were carried out on saturated sand reinforced with horizontal-vertical(H-V) inclusions of galvanized iron and perspex. The behavior of reinforced saturated sand was studied in terms of stress-strain relationship, pore pressures, shear strength of the soil and the failure situation of specimen. The influences of different vertical configurations of H-V reinforcing elements, confining pressures and reinforcing materials on the strength of reinforced saturated sand were discussed. The relationship between 3 dimensional reinforcing and geocell reinforcing was presented; and cavitation occurred in dilatant soils was discussed. It is shown that the peak deviator stress and shear strength at failure increase greatly for saturated sand reinforced with H-V elements as compared with unreinforced sand and sand reinforced with conventional horizontal inclusions, especially for those reinforced with galvanized iron sheet reinforcements. Meanwhile, reinforcements made of galvanized iron can improve the ductility of saturated sand.

The interaction mechanism of piles and slope soil is one of the important factors for the design of anti-sliding piles. On the basis of stress condition of the passive piles subjected to lateral force, the stress expression of arbitrary point of the soil behind the piles is derived from the basic theory of soil mechanics and elastic mechanics. Accordingly, the mechanical model of soil arch is created; and distribution of soil stress isolines is given. The shape of soil arch is found to be hyperbolic, shoulder expansion arch, saddle and domal which are distributed in different zones behind the pile groups. In addition, the mechanism of arching effect is completely interpreted; the relationship between pile spacing, pile width, distance behind piles and varying effect of soil arch are discussed in detail. Moreover, some factors influencing soil arching effect, such as inner friction angle and cohesion, are discussed as well. Furthermore, with regard to the problem of maximum pile spacing, in view of the stress condition of limiting equilibrium of soil at the arching crown, the control equation of maximum pile spacing is built based on the Mohr-Coulomb theory of soil shearing strength. Finally, a practical case of slope prevention engineering is studied for the design of pile spacing. This paper will play a great role for the realization of pile-slope interaction and contribute a lot to the theory of design of anti-sliding piles in the field of slope engineering.

Based on the measured data of several projects, the mechanical mechanism of the bit expanded anchor rod has been studied. It is pointed out that the mechanical process can be divided into three stages. The first stage is of earth pressure at rest. The second stage is of the transition phase, which is characterized by the displacement curve that has an inflection point. The third stage is of plastic zone compaction - expansion stage, which is characterized by the soil compaction body to strengthen and expand the head improved anchorage force. In this paper, several instances consistent with the above-mentioned mechanical process are given. According to Mohr-Coulomb strength theory, the calculation formula of anti-pullforce of the bit expanded anchor rod are deduced; and the expansion the first burial depth, soil cohesion, internal friction angle and other factors against the pulling force are analysed; and it is pointed out the shortcomings of the calculation method in current industry standard. Finally, an engineering example is given, and compared with the method of the text and the existing norms. It is shown that the results of the proposed method is more reasonable compared with experimental results. For engineering practice, it has achieved good technical and economic effects.

Transfer function analysis is an important method for obtaining dynamic characteristics parameters and estimating predictive dynamic response of vibration system. Through earthquake simulation shaking table model test of side slopes, transfer function of absolute acceleration and of relative acceleration could be obtained, which reflected the ground motion and the slope body’s seismic vibration respectively. Based on vibration equation analysis of elastomer and its demonstration model test of a side slope, calculation of dynamic characteristics parameters and predictive estimation of seismic response with transfer function analysis were studied. Two pieces of conclusion have been reached: First, in calculation of dynamic characteristics parameters, using the imaginary part of absolute or relative acceleration transfer function could get more reasonable and accurate result than using amplitude and real part. Second, the predictive Fourier spectra of slope’s seismic response could be estimated by multiplication of transfer function and Fourier spectra of input seismic excitation in frequency domain, and the estimation results was in accordance with model test data. It means that transfer function analysis is not only conducive to investigating slope’s essential response feature under complicated and various seismic motions, but also help to designing the shaking table board’s loading waveform of tests.

The dynamic deformation characteristics of coarse grained material are researched by large-scaled indoor triaxial test. The conclusions are that the dynamic stress-strain relationship of coarse granule doesn’t conform to the presumption of hyperbolic skeleton curve of Hardin-Drnevich under the situation of high stress, because of its volume becoming smaller. Therefore, an exponential stress-strain constitutive equation which reflect the vibration hardening of materials is proposed; the damping of coarse granule doesn’t conform to the Hardin presumption; an power function type of equation based on the experimental references is suggested; the seismic residual deformation of coarse granule is greatly associated with the initial density, static stress, dynamic load, duration of vibration and so on; the relationship between residual deformation and dynamic shearing stress of coarse granule is built considering the effect of initial consolidation confining stress. The research basis is provided for the construction of superhigh rockfill dam in meizoseismal areas.

The coarse granular aggregates equipped the state-depended characters is a kind of cohesiveless granular materials, of which stress-strain relationship depends on the density and stress level. The coarse granular aggregate is fragile, which is another character of it. Particle breakage of coarse granular aggregates modifies its structure directly, influencing its dilatancy, friction angle, strength and permeability. In order to accurately describe stress-strain relationship of coarse granular aggregates, the initial state parameter is applied to represent the interior state of the soil. The stress-strain relationship incorporating particle breakage energy is established according to triaxial test results, on which the dilatancy unified constitutive model of coarse granular aggregates is developed with associated plastic flow rule. The relationship between parameters of the current model and initial state parameter is developed. The unified constitutive model is developed, which incorporates not only the particle breakage influence exerting on dilatancy and friction angle, but also the dependence of stress-strain relationship on initial state. The parameters of model are determined by mutation particle swarm optimization algorithm, on which the triaxial test results are well simulated. The simulations are applied according to presumed initial state with the parameters determined above; the result indicates that the current model could simulate the transformation of coarse granular aggregates at various initial densities and stress levels.

The differences and relationships in compression index Cc and swelling index Cs of typical remolded Shanghai soft clay, measured using different test methods including isotropic compression-swelling tests and one-dimensional compression- swelling tests with or without K0 being measured, are studied. The deformation and strength of the soil are measured by drained triaxial compression tests, with different over-consolidation ratios and cell pressures. Also, the friction angle at critical state is determined from the test results. Finally, the coefficient of secondary consolidation of remolded Shanghai soft is studied using results of long-term oedometer tests with different vertical pressures. The parameters and preliminary conclusions from the above-mentioned investigations are valuable to engineering practices and establishment of constitutive model for Shanghai over-consolidated soft clay.

Jet grouting soil-cement-Pile strengthened Pile (JPP) is a new kind of composite pile composed of high pressure jet grouting pile and prestressed concrete core pile. In order to make a further research on load transfer mechanism of JPP under vertical loads, the full-scale model test of JPP, cast-in-place pile and jet grouting soil-cement pile have been done in the test room which is developed for this test. With the pre-arranged instrument in JPP, the axial stress, dip resistance and settlement of pile have been measured; and distribution of axial force and friction resistance are also analyzed. Experimental results show that: bearing capacity of JPP is thirty percent higher than that of cast-in-place pile which has the same length and diameter with JPP. The deformation of JPP is controlled by core pile; axial force distribution of PHC is different with soil-cement; and their axial force ratio in same section is their elastic modulus ratio. Distribution of inner and outer friction resistance is similar; and the inner friction is about 1.62 times of the outer one; it is about the ratio of JPP diameter and PHC diameter. Furthermore, the relation between friction resistance and relative displacement is similarly hyperbolic; and the relation between dip resistance and displacement is also hyperbolic.

Based on the theory of main stress axes rotation, the analytical expression of the lateral earth pressure coefficient of the soil overlying on the Trapdoor is presented; and the traditional Terzaghi loosening earth pressure is modified. For the cohesionless soil, the coefficient is only related to the effective internal friction angle of soil; and its value varies from 1.0 to the passive earth pressure coefficient Kp. It increases with the increase of the effective internal friction angle of the soil. For the cohesive soil, the modified Terzaghi loosening earth pressure is influenced by the thickness, unit weight, effective cohesion and the effective internal friction angle of the overlying soil on the Trapdoor as well as the trapdoor width. Compared with the traditional expressions, the proposed one of the Terzaghi loosening earth pressure is more in agreement with the experimental ones and FLAC numerical results. It can be used to analyze the soil-arching effect in the engineering of underground pipe, local subsidence of ground, tunnel and so on.

Undrained triaxial compressive tests were carried out on cemented soil to investigate the effects of confining pressure and cement ratio on the strength, pore water pressure and stiffness of cemented soil. It was observed that with the increase of confining pressure and cement ratio, the strength and stiffness increase and pore water pressure decreases. The stiffness decreases as the axial strain increased. The stiffness decreases greatly at the beginning of the tests and then the stiffness curves become smooth with a small degradation rate with the increase of axial strain. The relationship between normalized deviator stress and stiffness shows a nonlinear. With the increase of the normalized deviator stress, the normalized stiffness decreases. The stiffness degradation behavior of soft clay was described and Duncan-Chang model was modified. The parameters for modified Duncan-Chang model were obtained by regression. The comparison of simulation results with test data shows the modified model can simulate the strain-softening stress -strain relations of cemented soil.

An experimental method to investigate the long-term mechanical characteristics of loaded rockfill under different environmental conditions of drying and wetting, cooling and heating is presented. A series of tests were performed by using a newly developed weathering test apparatus to study the long-term degradation strain mechanism of argillaceous siltstone rockfill under different environmental conditions including drying and wetting cycles, cooling and heating cycles and the coupled wetting-cooling and drying-heating cycles. The test results show that the drying and wetting cycles and the coupled wetting-cooling and drying-heating cycles can induce remarkable additional strains of loaded rockfill, including wetting strain, wet-swelling and dry-shrinking strain and rockfill particle degradation strain. It is shown that the changes of environmental factors can cause degradation of rockfill particle; and the degradation strain of rockfill is a key portion of the long-term strain of high rockfill dam.

The smooth blasting parameters were researched in deep damaged rock tunnel in order to enhance its adaptability. Based on the theory functioned together by explosion shock wave and explosive gas-pressure, as well as the effect of high static stress and rock damage were also in consideration, parameter calculation formula of smooth blasting under the condition of deep damage rock mass tunnel was proposed through analyzing static stress in burden of perimeter, smooth blasting mechanism and vibration damage characteristics. The result shows that: (1) High rock static stress is equivalent to increasing of rock tensile strength, which make against to formation and transfixion of initial cracks, thus the hole space should be reduced. (2) After the rock was damaged, hole space of smooth blasting and the resistance line value can be appropriately increased while the other conditions are still the same. (3) Under the condition of high rock static stress and damage, surrounding rock with low stability can be easy damaged after smooth blasting when hole space is small. Therefore, the surrounding rock should be reinforced in time to ensure construction safety and rock mass stability as the blasting was improved. (4) The calculation formula of smooth blasting parameters proposed is proved to be valid and adaptable for complex rock environment in on-site blast operation.

To investigate the effect of compaction on the pore size distribution characteristic of laterite soil, the compacted soil samples which were firstly subjected to pressure plate to dehydrated to their residual water content were dried by liquid nitrogen freeze-drying method; and then the corresponding pore size distribution was measured. The results show that, among samples with different dry density, the differences of characteristics of pore size distribution are obvious in the case that the pore size is larger than 10 μm. And the greater the dry density is, the fewer the pores of soil in this scope. However, most of pores of samples are mainly distributed in the range where pore size is finer than 0.1 μm and their pore distribution density are almost the same, which means that conventional compaction of soil can only change the larger pore size, no significant change for the smaller one. This also indicates that the conventional compaction has a limit effect on the compactness of the roadbed which was filled with laterite soil.

Most parts of the Tianjin Binhai New Areas consist of lands formed by reclamation. The foundation soil is hydraulically filled materials and strengthened by vacuum preloading technique. Therefore, the soil in this region has some unique properties, such as the creep characteristics, which has great influences on the long term displacement and stability of the soil foundations of upper structures. The creep properties of undisturbed soil samples taken from construction sites in this area are tested under unconsolidated and undrained triaxial conditions. Based on the test data, a no-yield-surface constitutive model is established, which can simulate the creep properties of foundation soils in the Tianjin Binhai New Areas. The model contains five parameters that have definite physical meanings and can be determined with the test data. The predicted results with the established model agree well with the observed data through the tests. The numerical model can be used to estimate the long term displacements and stability of the soil foundations of existing structures.

Cyclic simple shear tests are conducted on a silty clay with different axial consolidation pressures; and nonlinear dynamic property curves, vs. curve and D vs. curve, of soil under different test consolidation pressures, where , and D are dynamic shear modulus, dynamic shear strain radio and damping ratio respectively, are obtained. Results indicate that even normalized dynamic property curves of soil under different consolidation pressures exhibit differences. Along with the build up of consolidation pressure, the degradation of curve slows down; and the increase of curve delays. Based on the experimental relationship between maximum dynamic shear modulus, maximum damping ratio, reference shear strain and the consolidation pressure separately, a novel consolidation pressure correlated dynamic property curve model of clay is proposed. Application of the consolidation pressure correlated model for site response is carried out. Results indicate that the property of soil dynamics varid with the consolidation pressure will affect not only the magnitude but also the frequency spectrum properties of the site response, and the thicker of overlay, the more obvious of the affects.

A well established constitutive model not only confidently simulates the stress-strain characteristics of geomaterials, but also properly reflects the lateral deformation of geomaterials; specifically, the generalized Poisson’s ratio shall be reliably figured out by using the constitutive model. Based on elliptic-parabolic yield surfaces model, a generalized Poisson’s ratio was derived to reflect the characteristics of geomaterials’ lateral deformation characteristics. Effects of main model parameters on the magnitude of Poisson’s ratio were analyzed. Parameters associated with dilatancy were found clearly affecting the generalized Poisson’s ratio. Based on the results of consolidated-drained triaxial shear tests of sand-expanded polystyrene (EPS) lightweight fills, verification was conducted with respect to the elliptic-parabolic yield surfaces model and the generalized Poisson’s ratio. It is shown that the model largely simulated the stress-strain characteristics of fills, so did the generalized Poisson’s ratio on describing fills’ deformation behavior, i. e. dilatancy, contraction and lateral deformation.

Considering the influence of preconsolidation pressure on permeability coefficients under normal consolidated state, the 3-D FEM numerical simulation of single drain was executed for vacuum preloading with software ABAQUS, which took the relations between permeability coefficients with consolidation stress into account. The results show that when the permeability varied with consolidation stress, the surface settlement magnitude is smaller and the course of consolidation is slower, which resulted in the time needed to finish consolidation is longer. Meanwhile, the research also shows that more the preconsolidation pressure, smaller the surface settlement is, and the time to the same consolidation degree is longer.

By using the resonant column device tests, the effect of the consolidation ratio on the maximum dynamic shear modulus (DSM) and the DSM versus the shear strain for two types of soils were investigated. The effect of the DSM versus the shear strain under different consolidation ratios on spectrum of surface ground motion was evaluated by the soil layer response calculation. An incremental formula for calculating the maximum DSM for the cases of the anisotropic consolidation was presented. The new formula indicates that the increasing degree of the maximum DSM due to kc>1.0 is significantly larger than that predicted by Hardin and Black’s formula. Compared with sand, the increment of the maximum DSM due to anisotropic consolidation is much larger than that of sand. Also, the effect of the consolidation ratios on DSM versus the shear strain and surface ground motion was demonstrated. The results indicate the DSM versus the shear strain increases with increasing of the consolidation ratios and the effects of the consolidation ratio on DSM versus the shear strain should be considered for the incidence of the strong earthquake.

Soil water characteristic curve (SWCC) is an important concept in unsaturated soil mechanics; and current research work requires SWCC to reflect more contents and factors. Among the factors influencing the SWCC, the influence from soil density is common and important. Research on how to mathematically describe the influence of soil density on SWCC is carried out. Based on the capillary model and Childs’ (1950) statistical assumption, the motion law of the point on a SWCC in the situation of density variation is found; and an empirical method for estimating the SWCC corresponding to different initial soil densities based on two SWCCs with determined densities is proposed. Comparing the predicted results with experimental findings, a good precision is found. As the determination of SWCC from experiments is time consuming, predicting SWCC with different densities through this method can greatly reduce the workload of experiments, which can make the usage of SWCC in practice more convenient; besides, more influencing factors can also be considered.

Based on the dry-wet cycling experiment of concrete and micromechanics, the study of mechanical properties of concrete in seawater erosion is carried out. In the aspect of dry-wet cycling, by accelerated corrosion test method, the experiment of concrete specimens and mortar specimens which are made according to the ratio of concrete, has been completed after 0, 10, 20, 30, 40 and 50 times dry-wet cycles. Under the influence of seawater erosion on the concrete, its compressive strength is tested, together with the tensile strength of concrete, elastic modulus and stress-strain relationship, using the large static-dynamic triaxial test system for concrete. According to the theory of micromechanics, the concrete test block is numerically simulated on meso-level. Considering various components, the material nature of its components is assigned in accordance with the Weibull distribution. In order to reflect the influence of seawater erosion on the concrete, the strength and elastic ratio of mortar specimens are assigned according to the result of dry-wet cycling experiment. Finally, through the analysis and study of the concrete above all, the compressive strength reduction model, the tensile strength reduction model, and the elastic ratio reduction model, are determined with the change in the number of dry-wet circle.

Soft clay has characteristics such as high moisture content and large void ratio. After excess pore water stress dissipation under loading, secondary consolidation settlement is produced. A lot of geotechnical engineering problems are caused by it and it is necessary to calculate and predict the settlement. The general secondary consolidation settlement calculation method has a shortage that when load duration is infinite, settlement infinite. An improved formula is presented aiming at the shortcoming. Brief review is given on Yin & Graham 1-D elastic viscoplastic model and improvement is given on it. A method to determine starting and finishing time of secondary consolidation settlement of soft foundation is put forward combined with the improved elastic viscoplastic model. The improved formula is feasible and more reasonable and can be used to calculate secondary consolidation settlement of foundation in actual engineering

Based on the dynamic response characteristic of concrete, the dynamic response of spherical cavity expansion for conventional projectile velocity is divided into three regions, i.e. elastic, cracked and voids compacted regions. The constitutive description of voids compacted region idealized pressure-volumetric strain as bilinear compressible and idealized shear strength pressure as Mohr-Coulomb criterion with a tension cutoff. The dynamic response expression of spherical cavity expansion is derived by similarity methods; and the dynamic response numerical solution is given by Runge-Kutta-Felbberg numerical method. The results show that the predictions from the penetration model based on the theory are consistent with experiment data.

Through analyzing the mechanism of flow slide of loess landslides, it can find the steady state strength (residual strength) plays a major role. The evaluation of residual strength requires a better understanding of undrained saturated loess behavior. The steady strength of saturated loess is discussed under stress-controlled undrained consolidation triaxial test. There are two typical stress-strain behaviors of saturated loess: steady state behavior and quasi-steady state. In majority situations, it exhibits steady state behavior. Only loose loess exhibits quasi-steady state behavior. According to the test results, steady state line and steady state strength line of saturated loess are obtained. These lines can be used to analyze the mechanism of flow slide. The existence and uniqueness of steady state line are proofed. The internal friction angle and cohesion can be used to describe the steady state behavior of saturated loess. The meaning of these parameters is discussed. The difference of saturated loess and sand is analyzed.

Slab foundation underpinning method is an effective method to develop underground space in existing buildings, which weight can be supported by partial top slabs and base slabs by turns. The additional internal forces caused by differential settlement in underpinning affect the safety of existing buildings. The slab foundation underpinning process was divided into five conditions: top slabs underpinning, soil excavation around top slabs, lengthening columns, base slabs underpinning, and soil excavation under top slabs. In order to study settlement law ,a 1:10 model test was done, in which settlement values of every conduction can be obtained by the dial indicator installed on standing post. The differential settlements can be calculated using the settlement values. The test results indicate that the settlements of column-heels in middle part were larger than ones in around part during the process of top slabs underpinning, soil excavation around top slabs and lengthening columns conditions; while, the settlements of column-heels in middle part were smaller than ones in around part during the process of base slabs underpinning and soil excavation under top slabs conditions. The biggest differential settlement was produced in the lengthening columns, which was reduced after the base slabs underpinning. Therefore, lengthening columns is the most unfavorable condition for causing the biggest additional internal force.

The traditional model of wedge for stability analysis of tunnel face under homogenous soil is extended to encompass multilayer soil with seepage; the wedge consists of trapezoids and each trapezoid is related to a layer of soil; the Terzaghi’s theory and upper limit theorem are applied to derive the equation for limit support pressure. The limit support pressure is the sum of the effective support pressure and seepage force; the former is obtained from limit equilibrium analysis and the latter is evaluated by means of numerical analysis of head distribution. It is found that the seepage force is the main portion of the limit support pressure. The analytical results are consistent with measured data in engineering.

An analysis procedure based on shear strength reduction finite element method for pseudo-static seismic stability calculation of earth and rockfill dam (ERFD) is presented. In the proposed procedure, two methods are proposed to determine the seism-induced inertia force: (1) the inertia forces are computed with the same method adopted in the pseudo-static limit equilibrium slices method; (2) with the absolute acceleration response of element nodes obtained from the finite element dynamic response analysis of the dam, the inertia forces corresponding to the node acceleration are computed with the proposed empirical method. With the inertia forces achieved above, the self-gravity, and/or the forces corresponding to the seepage force or dynamic pore water pressure, the elastoplastic finite element analysis is conducted to achieve the pseudo-static factor of safety of the dam by reducing the effective shear strength parameters of soil until the limit equilibrium is reached. Finally, numerical computations are conducted to illustrate the proposed analysis method; and the results are compared with those obtained from the pseudo-static limit equilibrium method. It is concluded that the utilization of the finite element method for aseismic stability analysis of ERFD is feasible.

The four forepoling schemes such as horizontal drilling jet-grouting peg, full face deep boring grouting, long pipe roof grouting, space between-reduced little tremie grouting with constructing temporary invert, which were possibly adopted to the tunnel crossing river and bridge on line 5 of Beijing metro, were analyzed initially by using engineering experience. The comparison shows that the scheme of space between-reduced little tremie grouting has superiority in construction cost as well as rate of tunnelling and construction impact. Then, the scheme of long pipe roof grouting as well as the scheme of space between-reduced little tremie grouting were evaluated farther and compared by using three-dimensional numerical simulation. The numerical simulation results show that the impact on the bridge abutments, bridge piers and river bottom stratum produced in the scheme of long pipe roof grouting and the scheme of space between-reduced little tremie grouting respectively is equivalent in the condition of taking no account of stratum advance disturbance caused by the construction of long pipe roof. Therefore, the scheme of space between-reduced little tremie grouting will exceed the scheme of long pipe roof grouting in the condition of taking account of stratum advance disturbance caused by the construction of long pipe roof. The long pipe roofs as well as little tremies and foot-locking little tremies bear smaller bending moment. The foot-locking little tremies and little tremies belonging to tunnel crown will bear the axial pressure; little tremies belonging to tunnel side will bear both axial pressure and axial tensile force, while long pipe roofs will suffer mostly axial tensile force.

Madaozi Iron Ore Mine lies on the east of Boziliang auxiliary dam of Panjiakou Reservoir. The distance between the mine and the auxiliary dam is only about 160 m. So it is a very important question for discussion whether mining will affect the safety of the auxiliary dam. A large-scale mapping in the study area was done by 3D laser scanner; and a 3D geological model was established. The strength of rocks was tested with a schmidt hammer and a dot-loading apparatus; and statistics of joints and fractures were carried out under the well. Based on these, rock mass classification was made with RMR-system; and the strength parameters of surrounding rock were determined. The regular pattern of the surface movement causing by iron ore mining was forecast with the FLAC-3D software. Finally, the seepage field of Boziliang auxiliary dam was simulated and analyzed using the Visual Modflow software. The study result indicates it will not affect the safety of Boziliang auxiliary dam as long as the exploitation in Madaozi Iron Ore Mine conforms to design.

According to blasting vibration live data that have been collected, the time-frequency characteristics analysis for blasting vibration signals has made by wavelet packet analysis technology. According to the multi-resolution decomposition of wavelet packet transform, the wavelet packet frequency band energy has been deduced on different bands of blasting vibration signals; and it can reflect the total influence of all the three key elements (intensity, frequency and duration of vibration) of blasting vibration. Energy distributions for different frequency bands of blasting vibration signals are obtained based on wavelet packet energy spectra. Based on the characteristics of dynamic response from the controlled structures by blasting vibration, it is firstly established that a multi-factors blasting vibration safety criterion called response energy criterion. The criterion can reflect the total influence of the intensity, frequency and duration of vibration and the characteristics (natural frequency and damping ratio) of dynamic response from the controlled structures themselves; and the feasibility and reliability of the criterion are validated by the instances. Compared with velocity-frequency safety criterion, this criterion can describe accurately the degree of effect on the controlled structures by blasting vibration, and evaluate more comprehensively blasting seismic effect on the structures.

Technology of blast-induced caving roof based on the successive mining, it is said that the caving zone of fracturing are controlled through the pre-splitting blasting and inducing fracture are developed by the forced blasting. With the development and expanding of the cracks, the rock mass would have been instability and caving in the roof. But, to the process of the induction caving roof by blasting in the underground mine, the effects were invisible to the pre-splitting blasting and the forced blasting. It is difficult to quantitatively evaluate the effect of blasting. Using the borehole camera system, the technique of front view and digital panorama were used to inspect the effect of blasting. The shape of the hole-wall was detected before blasting, and the effect of the inducing fracture was inspected after blasting in the hole-wall. Especially, the cracks character was described by the digital panoramic borehole camera. The photographs were analyzed by the view and digital method. The results of the digital panoramic borehole camera show: (1) The pre-splitting cracks had been formed after pre-splitting blasting. Its width is up to 20-40 mm; and the half wall of hole could be seen in the bottom. (2) Large of secondary cracks were formed in the rock mass of roof, the crack form is “X”. And the original cracks were expanded. (3) The mass shapes of blasting was right, the rock stacked by the natural angle of slope. It is advantage to induction caving roof to the large cracks and ruptured structural rock mass.

3-D dynamical response analysis of concrete-faced rockfill dam is presented. Using equivalent-linear model, for different dam heights and different shapes of river valley, the responses of dam subjected to different seismic wave inputs have been studied. The results show that on the condition of the same dam height and the base acceleration excitations unchanged, with the increase of the river valley width, the position of the maximum acceleration on the axis of the top moves from the middle to the riversides symmetrically. To the narrow river valley, the position of the maximum acceleration which occurs near the riversides to the wide valley is on the middle of the axis at the top. The result negates the application of 2-D dynamical computation for wide valleys, and shows that for the seismic response of high concrete-faced rockfill dams, the seismic amplification factor along the axis should be given, except for that along the dam heights.

The change of pore water pressure and soil effective stress in foundation pit base, subjected to fast increase of confined water pressure due to sudden rise of the influent river during flood peak, have been analyzed. Based on soil permeability and its two damage mechanisms (i.e. tensile failure and shear failure), a new method for determining critical thickness of base plate of foundation pit is presented based on elastic theory. The new method is compared with traditional method to calculate the critical thickness of base soil of foundation pit by case study. Results show that the new method considering indices cu, ?u, and the size of foundation pit base, is more reasonable than the traditional method. However, the results calculated by the method in this paper reduce to the results by traditional method as for highly permeable soil like sand.

It is pointed out that the conventional method such as Bishop method is not incorrect itself for the stablity analysis of expansive soil slope, and only related conditions being short so as to cause the stability analysis cannot reflect the actual landslide characteristics. Based on the Bishop method, the factors are considered with introducing of the related conditions, which include the strength attenuation due to the cracking evolution, the depth of cracking, water pressure in cracks and the seepage force caused by rainfall. Thus the analytical method of slope stability in expansive soil areas is advanced so as to reflect the effect of cracking on the stability of expansive soil slope and the collapse features of expansive soil slope such as shallow layer, gradual traction, long-term, gentle and seasonal characteristics have been reproduced actually by the computed results.

A 1:10 scale shaking table model test was conducted by a large-scale laminar shear box; the test mainly researched on cement fly-ash gravel (CFG) column-net composite foundation, with the saturated silty soil ground of the Beijing-Shanghai High Speed Railway which was treated by CFG column-net. It has been plot that the amplification coefficient distribution of response acceleration under a series of input acceleration seismic loads, and the relation between the series of input accelerations and its corresponding amplification coefficient of response acceleration. The results show that: (1) at less than 0.101g loading acceleration, the response acceleration scarcely enlarge and its nephogram presents a horizontal type distribution; (2) at 0.161g loading acceleration, as a result of liquefaction of soil between piles, the respone acceleration greatly increase; (3) at 0.210g loading acceleration, the response acceleration increase result from liquefaction of soil between piles and shear break of CFG column; (4) at 0.324g, 0.363g loading acceleration, the integral rigidity of foundation decreases greatly, which reduces its capability of the shock transferred and result in the response acceleraton is less than that at the former loading acceleration; (5) during the course of loading acceleration, amplification effect of response acceleration is obvious in silty soil, but not in clay layer.

In the design of pit support structure, the design of the pit-in-pit had a direct impact on security and economy of the support structure. Furthermore, a few of the excavation support structure accidents were closely related to unreasonable design of the pit-in-pit. Taking a soil nailing wall instability for example, the fundamental reason for the crash of the excavation support structure was analyzed. The method of reinforcement design was developed; but also the design method of the pit-in-pit was put forward. Mutual control and mutual influence between the foundation pit and the pit-in-pit were studied. Research shows that: the pit-in-pit of the basement foundation pit has a greater impact on the whole stability of the support structure; while the foundation pit support has a relatively smaller impact on the internal forces of the supporting piles in the pit-in-pit.

Grouted gravel pile is a new technique of pile construction, load-bearing characteristics of grouted gravel pile composite foundation is analyzed based on its application to soft subgrade improvement of Ningbo round-city expressway. The settlement and lateral deformations of the subgrade are monitored in-situ; while the pore pressure, earth pressure between piles and pressure on the top of piles are also monitored. The monitor result indicates that: the total settlements are small and soon became stabilization, which is propitious for the construction; stress concentration on the top of piles is evident, which proved the replacement effect of pile is evident; pore pressure decreased soon, which reduced settlement after construction caused by secondary consolidation.

In order to study the rule of pile floatation in prefabricated pile construction, in-situ test for pile floatation in prefabricated pile construction in Wenzhou has been carried out systematically. Test results hold that pile floatation is related to construction distance and construction order. In addition, pile floatation is larger when pile construction quantity per date is more, pile final-pressure value is higher and soil on the periphery of pile is harder. According to test data, it is found that pile floatation is different with different pile penetration length, but the pile penetration speed doesn’t influence on pile floatation speed. What’s more, pile pre-drill hole, release hole as well as barrier can reduce effectively pile floating. Finally, the paper suggests redriving pressure value determination must be based on local experience in relation of the single pile vertical supporting capacity characteristic value, soil characteristics, pile length as well as the pile supporting level.

In light of the effective length problem of super-long pile of the pile group in highway bridges, the loading status of pile foundation for highway bridges in China is statistically analyzed. The resulting stress distribution range at the top of the pile is basically 6-21 MPa. The model tests of the super long pile groups have been carried out, in which the length-diameter ratio is 96 and the pile spans are respectively 3D, 4.5D and 6D. The axial force distributions of different loadings in the super-long pile group with different pile spans are obtained. According to the depth of pile section for axial forces of the pile tending to zero, the effective length of pile is determined. The relations between the pile top stress and the effective length of pile for three different pile spans are drawn up by utilizing the exponential functions. By exploring the resemble principles about model test of pile groups under the vertical loads, the effective length of piles corresponding to pile top loading of the super long pile group in highway bridges are yielded. Also the relations between the effective lengths of piles in the super long pile group and the pile spans are researched. At last, some suggestions are proposed for the concrete choice data of the pile spans and effective lengths of super-long piles.

The experiment of explosion wave propagation in saturated soils is accomplished in the ? 2.5 m×5 m pothole. Free-field experiments of explosion with different burial depths in saturated soils are carried out. The macro characteristics of explosion and recorded waveforms of pressure are presented. The recorded results are interpreted. The propagation laws of shock wave in saturated soil, the data of coupling coefficient and the coupling coefficient curve are obtained. The experiments show that the minimal scaled buried depth is 2.62 m/kg1/3 for close explosion in free-field. When the minimal scaled buried depth exceeds 2.62 m/kg1/3, the peak pressure and momentum influenced by the scaled buried depth is very little. At this point the mostly energy of explosion is closed in saturated soils.

According to the research status of construction spatial effects in large-long-deep foundation pit that is mainly focusing on the numerical simulation, but theoretical research is not too many till now. A simplified method for calculating the construction spatial effects of large-long-deep foundation pit in cohesive soil was advanced. The soil layers around deep foundation pit were equal to cohesionless isotropic soil mass by introducing the concept of equivalent internal friction angle. And then, by means of limit equilibrium analysis method combined with soil plasticity upper bound theory and associated flow rule, the spatial effects of two 3D failure modes: tension crack-shear and pure shear in deep foundation pit were studied concretely; and the corresponding formulas of spatial effects coefficient were put forward; also two examples were analyzed. The research results indicate that the method, which can complete by hand-calculation, avoids the defects of low efficiency, high cost and long period in numerical simulation, and the distribution characteristics and value size of spatial effects coefficient could be obtained directly from its calculation results, which can be used as guidance for the supporting structure, construction scheme design and the test points or sections choice in process of information monitoring.

A coupled chemoplastic-damage constitutive model for the simulation of coupled chemo-thermo-hygro-mechanical behavior of concretes at high temperature is proposed. A consistent return mapping algorithm for the integration of the rate coupled constitutive equations is developed. Consistent tangent modulus matrices for coupled chemo-thermo-hygro-mechanical analysis are derived to preserve the quadratic rate of convergence of the global Newton iterative procedure. Numerical results demonstrate that the proposed constitutive model in reproducing coupled chemo-thermo-hygro-mechanical behavior of concretes subjected to fire and thermal radiation is available and effective.

In order to know the mechanical effect and the stability of the Ming Tombs Reservoir dam influenced by the dynamic loading and the environment condition during the Olympic game, the optimum elastic modulus scheme of the inclined clay wall, gravelly coarse sand and sandy cushion layer, which are the three main soil layers of the dam, is back analyzed by utilizing the orthogonal experiment design and based on in-situ measured deformation from the load response of the Olympic construction, including the spectator stand and the temporary facilities. The numerical simulations of the processes of initial Olympic construction and the dynamic loading-unloading cycles during the Olympic game are carried out by utilizing the obtained optimum parameters. The results show that the maximum settlement produced in the dam during the game is about 7.4 mm; and the maximum horizontal displacement is not over 1 mm; and the dam is safe and stable during the game and after the game; and the shear damage and tensile cracks do not appear. The monitored deformations during the game are close to the results of the numerical simulations, which indicates that the numerical simulations based on the parameters obtained by back analysis of in- situ measured displacements can make the scientific prediction and the quantitative evaluation for dams.

Based on Biot's dynamic poroelastic theory, a system of rail pad, sleeper, ballast and double layers of transversely isotropic saturated subgrade is proposed, in which the system can be decomposed as a track system and a double layered soil system. Applying the double Fourier transformation technique to the track system and the soil layer system, the governing equation of track-layered transversely isotropic saturated subgrade system is simplified as an eigenvalue problem for solving a 6 order governing equation. The solutions of the dynamic response of track system-double layered transversely isotropic saturated subgrade to train loads are derived in the transformation domain. Numerical results are obtained by using the inverse fast Fourier transform(IFFT); and then the IFFT are used to analyze the influence of the modulus and Poisson ratio of the first and the second layer of soil on the displacement, pore pressure and shear stress. It is shown that there are great influence of the stiffness of soil layers on the dynamic response; and the influence of modulus are greater than that of Poisson ratio. The computational results can serve as a reference for determination of the reinforcement depth in the soft subgrade.

The genetic mechanism and evolvement process of the reservoir bank landslide were discussed detailedly based on engineering exploration and analyzing environmental geological conditions. And some main factors effecting stability of the landslide were analyzed emphatically. Through building a 3D FEM model of landslide, the stable situations of the landslide under various situations were considered based on the strength reduction method. The result shows that the landslide is steady under the natural situation. The front edge of the landslide will be drowned out when the reservoir retains water normally; the safety factor reduces and can’t meet the requirements of norms. The landslide tends to be more dangerous under rainfall infiltration and rapid drawdown of the reservoir water level. And the landslide will be instable when water storage situation and earthquake situation were considered at the same time. According to the preceding analysis, the treatment measures of cutting slope and reducing load were presented. The landslide is steady under various conditions after being controlled. The relevant conclusions and methods proposed take a good effect in landslide treatment.

The Interaction factor method is a kind of effective numerical methods to analyze pile groups; and the key point of this method is to get the interaction factors. The parameter computed by the traditional elastic method is lager than the real interaction. The new method to compute the interaction factors by the FEM considering the pile soil sliding and the elastoplasticity of soil is presented; and the simplified analysis method of pile groups is established. The influences of various parameters on interaction factors are studied by ABAQUS. Different methods are compared on the two history cases; and the results show that the new method by FEM is more suitable for the analysis of the real engineering cases.

Present designers of soil-nailing walls consider the facing as accessory structure rather than the main one, and all active earth pressures of soil-nailing walls are born by nails. However It is absolutely sure that the facing bear against water and earth pressure. Facing isolated and considered as finite beam on elastic foundation simply, solutions of displacement, angles of rotation, bending moment and shear force of soil-nailing walls are gained on basis of field tests in layered soil. Rationality of the model is tested and verified. The results that can disclose laws of distribution of facing earth pressure are in agreement with the actual measurement data. Earth pressure in bounding surface shows abrupt changes while displacement of facing exhibits continuous characteristics. Earth pressure of facing applied by soft soil presents bigger values than that of hard soil. Earth pressure in “upper soft and lower hard layers” can be easily gained than that of “lower soft and upper hard layers” soils. The laws of facing earth pressure in various soil layers are studied that the curves of earth pressure in good layers such as sand soil and hard plastic clay have characteristics of zigzag shape rather than smooth one in bad soil layers of silt soil and soft plastic clay. At the meantime, ratios of earth pressure to nail tension are calculated; and effects of facing on earth pressure become clearer and clear with depth of pit excavation. The ratios of earth pressure to nail tension become larger with excavation depth. In order to meet the necessity of mechanics of soil-nailing walls, rations of facing earth pressure to nail tension in various soil layers and depths should be put forward for references. The results and the method of calculating above ratios based on precise elasticity theory are very significant and have engineering use value for further research of mechanics of soil-nailing walls and for designers considering the facing action against earth pressure.

It is necessary to clarify the data types of strata information system and their features based on the concept of the geological entity. The data of strata information system are summed to 4 categories, namely the attribute data, geometric data, relation data, metadata. Geological entities are divided to basic geological entities and geological entity elements; and the latter are further divided to connection elements and non-connection elements. The geometric properties of ore bodies, weathering interfaces, faults, folds, unconformity planes and sliding bodies are analyzed. With the difference between locations of the observer, data gathering and data corresponding to considered, the concepts of surface survey, driving-in survey, stratum perspective survey and stratum non-perspective survey are proposed as a classification of geological investigation methods; and the corresponding relationships between raw data and geological entities are analyzed.

Taking into account of seepage force, the elastoplastic solution of circular openings is derived by using Hoek-Brown failure criterion. The ground reaction curve, relation curve between radius of plastic zone and supporting force of tunnel wall and relation curve between radius of plastic zone and gravity stress of rock mass based on Hoek-Brown failure criterion are drawn, with seepage being considered. By comparing with the curves based on Mohr-Coulomb yield criterion and the curves without considering seepage, we concluded that: the radial displacement of tunnel wall and radius of plastic zone by Hoek-Brown failure criterion are larger than the results by Mohr-Coulomb yield criterion. For good quality rock masses, the radius of plastic zone based on Hoek-Brown failure criterion is much larger than the results by Mohr-Coulomb criterion. The effect of seepage effect on the radius of plastic zone and radial displacement of tunnel wall for underground opening is significant.

Based on long term displacement monitoring data of high rock slope, the factors of slope displacement are presented firstly. Then the monitoring model for high rock slope, called nonlinear time series evolution statistic monitoring model is established. It is also applied to the high slope project of Jinping Hydropower Station. Time-effect and rainfall are assumed as two main factors of high slope displacement; and their formulas are also presented through the analysis of long term monitoring data. The parameters of the monitoring model are obtained by the nonlinear regression technique on the platform of Matlab. Meanwhile the monitoring model is improved by using ARMA method to fit and predict the residual of regression of slope displacement. The result shows that the monitoring model can characterize the behavior of high slope displacement and has a reliable fitting and predicting precision.

Aimed at problems lying in the exiting methods for calculation of laterally loaded piles installed in multi-layered soils, the method based on elastic theory and the stress-strain relationship of the pile-soil, the variation equation are obtained using the principle of minimum potential energy, the variation equations are solved analytically using the method of initial parameters. The computations and post processing for displacement and internal forces of PCC were programmed. It is shown by computation and comparison of model test that the calculated results by the method coincided very well. Meanwhile, the method is more precise and efficient than the existing conversion methods of subgrade modulus. Therefore, it could be useful for the design and analysis of PCC under lateral load.

Soil-aggregate mixture is composed of gravel or cobble as its coarse grain and clay or sand as its filling. Whether natural or man-made, the mechanical properties of this material are widely different from homogeneous and continuous soil or rock. The engineering background of this paper is the high fill of Kunming new airport project in which a large number of soil-aggregate mixtures will be used as filling material. Through the numerical simulation of confined compression tests with 3D particle flow models, we compared the micromechanical fabrication and basic mechanical properties of the soil-aggregate mixture with different grain size distributions. Then we put forward a zone of the ratio of rock to soil which could be used in the project. The influence of different ratios of the stone in the mixture to their fabrication was also investigated. This simulation is a valuable attempt for application of particle flow method to practical engineering project.

Elastic waves are excited by the linear impact force with several periods at the boundary of the underground cylindrical cavity to detect underground cylindrical pipes. It is a transient acoustic field. Based on wave functions expansion method, the waves in the field are expressed in terms of wave potentials and expanded in Fourier-Bessel series, and the coefficients in the wave functions are determined to satisfy the boundary conditions. Thus, the analytical solutions of the potential functions of the field are obtained. Then the numerical results present the waves propagating process and the relationships of energy. Furthermore, the amplitude of the reflected signals is influenced by the material parameters of the pipes; and the results are determined by the matching raw of acoustic impedance. These conclusions and experimental results are in good agreement.

A mathematical model for fluid-solid coupling in reservoir was constructed based on the equilibrium equation of solid skeleton and continuity equation of wetting liquid in porous medium. Jaumann stress rate formula was adopted to describe the finite deformation behavior. The effects such as in situ stress, initial pore pressure, initial fluid density and initial porosity of the medium was also taken into account in the mathematical model. Finite element discretization was carried out on the mathematical model to get a fully coupled finite element equation with the parameters of element nodal displacement and element nodal pore pressure as unknown variables. Finally, the transient nonlinear finite element equation in incremental form for reservoir fluid-solid coupling is obtained by means of time discretization in implicit difference scheme. The resulted finite element formulation can simulate the reservoir behavior comprehensively and would have wide applications in petroleum engineering.

According to the interior stability problem of the soil-nailing wall, a global optimal algorithm, which can locate the critical arbitrary slip surface associated with the minimum safety factor, is proposed. Firstly, based on Morgenstern-Price limited equilibrium method and by considering the consolidation of soil nail, a new computation formula of stability safety factor for the soil-nailing wall is presented. Then, the disadvantages of the simple genetic algorithm (SGA) and the tabu search algorithm (TSA) are following analyzed. Furthermore, the adaptive genetic algorithm (AGA) is also introduced. Through substituting the tabu mutation operator (TM) for the mutation operator of AGA, a new type of optimal algorithm, i.e. the adaptive tabu mutation operator and genetic algorithm (ATMGA) is proposed. Applying the ATMGA into the field of soil-nailing wall interior stability analysis, an optimal algorithm for searching the arbitrary critical slip surface is established. The simulating calculation results show that: (1) compared with SGA, TSA, and AGA, the ATMGA not only has the merits of high searching efficiency and fast converging velocity but also can exactly seek out the critical slip surface and the corresponding global minimal safety factor. (2) There is a significant difference between the critical slip surface of the unconsolidated wall and the soil-nailing wall, it is also suggested that it is necessary to seek out the critical slip surface and its safe factory of the soil-nailing wall in practical foundation pit engineering.

Based on the displacement sequence of slope, the stability of slope could be judged effectively by forecasting the displacement of slope in the future. Through analyzing advantages and disadvantages of grey forecasting methods and least square support vector machines(LSSVM) respectively , a new forecasting model of grey least square support vector machine was proposed. The new model not only developed the advantages of accumulation generation of the grey forecasting method, weakened the effect of stochastic-disturbing factors in original sequence and strengthened the regularity of data, but also used the quickly solving speed and the excellent characteristics of least square support vector machines for nonlinear relationship and avoided the theoretical defects existing in the grey forecasting model. At the same time, the genetic algorithms were used to optimize the parameters of new model. At last, two engineering examples are given to testify the effectiveness of the grey least square support vector machine method to forecast displacements of slope; the results show that the new model has higher precision.

Composite element method (CEM) is a numerical method suitable for discontinuous media structure. The main advantages of CEM are that the discontinuities can be ignored when creating grid, but the discontinuities can be explicitly simulated when calculating. Based on composite element model for static analysis, the composite element model for dynamic analysis is implemented. The formulas of mass matrix and damping matrix for dynamic analysis of CEM are presented. According to mass matrix, stiffness matrix and damping matrix, the inertial forces and the damping forces in composite element are converted to the generalized nodes. The control equations for dynamic system of CEM subjected to the inertia forces, the damping forces, the dynamic loads and the elastic forces are formulated. A seismic example of a concrete gravity dam on a rock base with two faults is computed by the CEM dynamic analysis program. The results meet well with the solution of finite element method (FEM). It shows the validity and effectiveness of the new method.