This article presents each of the current analytical methods used in rock and soil mechanics through CT number research avail of observation, wasting the precious quantitative information of CT datum. Utilizing the set theory and the measure theory, the concepts of the λ level damage-fracture ratio and the λ level damage-fracture rate, the (λ1－λ2) level intercepted section ratio and rate are defined based on the CT number, simultaneously furthering to research the relation among the λ level damage-fracture rate, the CT number and the density. The position and damage-fracture criterion are studied. Based on the conception of the intercepted section in the damage-fracture space, the rock and soil material is classified as the safety zone, the damaging zone and the fractured zone, the upper and the lower boundary surface of the damaging zone are studied. Meanwhile, the paper defining the rules of intensifying and damaging, establishing the rock and soil mass constitutive relation of the divisional damage-fracture space, simultaneously furthering to deduce the basic equations of the rock and soil damage-fracture space theory.

The studies with development of piping and filters, two mutualized problems, are reviewed. Meanwhile our studied results are also given for comparison. This part II, with respect to filters we indicate that the developing tendency of controlled grain size is one point of average grain size first and then to two points as well as to many points along the grain size grading curve. Terzaghi’s filter criterion is conservative and it should be revised by hydrodynamics in spite of sand gravel filter or geotextile filter. When filter used to protect clay the key problem will be cracked or not and the design criteria for these two situations are very discrepant. As to clogging of filter, such as relief wells, the suction washing method to restore the drainage effect is the better.

The series solution for the scattering of plane P and SV waves by an underground circular lined tunnel is used to quantitatively analyze the effects of incident wavelength, incident angle, diameter of tunnel, and liner stiffness on ground surface displacement amplification. The numerical results show that, the effects is not large for incident low-frequency waves; the surface displacement amplitude with a tunnel can be 4.5 times of that for the case of without the tunnel; the surface displacement amplitude with a lined tunnel can be 87.8% more than that without the liner. It is suggested that the effects of a tunnel on ground motion should be considered when the tunnel is planned and designed.

Firstly based on the triaxial rheological curves of greenschist specimen on rock servo-controlling rheology equipment, five-component viscoelastic model is put forward to identify the curves that show the viscoelastic rheological properties, which gets the viscoelastic rheological parameters of greenschist. Then a new nonlinear viscous component is put forward. When nonlinear viscous component is parallel connected with the plastic component, a new nonlinear viscoplastic body (NVPB) can be gotten, which may reflect the accelerative rheological properties of rock. At the same time, by connecting NVPB model and five-component viscoelastic model in series, we can construct a new seven-component nonlinear viscoelastoplastic rheological model of rock. Then using complete accelerative rheological curve, proposed seven-component nonlinear viscoelastoplastic rheological model of rock is carried out the identification. The correlative parameters of nonlinear rheological model such as viscoelastic modulus and viscosity etc. are also gained. The comparison between the rheological model and experimental result shows that the nonlinear rheological model is right and reasonable.

The volumetric strain due to dilatancy of soil-structure interface was studied based on test results. It is found to be composed of a reversible and an irreversible dilatancy component. The irreversible dilatancy component reflects the evolution of physical state including crushing and compression of the soil. And it exhibits similar change tendency to the evolution of stress-strain relationship response. Thus, the irreversible dilatancy component could be used to measure the evolution of the behavior of the interface. The reversible dilatancy component would dilate after the compression at first due to shear application. And it obviously exhibits aeolotropical behavior, which is induced by the structural aerotropy of soil near the structure due to shear application. The dilatancy equation was derived through introducing new concepts such as effective shear strain according to mechanism analysis.

On the basis of compositional characteristics of the colluvial landslide induced by rainfall, the model and equation of displacement dynamics of colluvial slope have been established. And then, the displacement dynamic pattern and features and the quantitative relationship between displacement and groundwater table or rainfall are analyzed. And it is found that the displacement dynamic features of colluvial slope are mostly determined by the groundwater table and its changing law and that there is a strong wave in displacement and velocity of displacement before the overall sliding of a slope. All the displacement dynamic laws show that it is not reasonable to use the single displacement response parameter of displacement or velocity of displacement to make the judgment and prediction of the stability of this kind of slope. Therefore, it will have a very significant and practical value to establish a multi-parameters prediction theory and model of displacement of the colluvial landslides.

The anisotropic elastoplastic model of layered soil is established to solve seismic response analysis of shield tunnel systems in layered soil. The doubly asymptotic multi-directional transmitting boundary for transversely isotropic medium is formed. Based on anisotropic elastoplastic model of layered soil, the dynamic finite element program of layered, transversely isotropic soil-structure dynamic interaction is developed according to the characteristics of aseismic design for shield tunnel. To simulate shield tunnel with finite element, various stress-strain models and element models are adopted in the program. The seismic response analysis of the district tunnel of Metro Line No.2 in Shanghai is carried out using the developed finite element program. The calculation results show that the dynamic finite element model of layered, transversely isotropic soil-structure is feasible and applicable. And the results show that it is necessary to take account of anisotropy of layered soil effect in the seismic analysis of shield tunnel system in layered soil.

A new constitutive model of sand considering complex stress path has been proposed. It offers an insight into a fact that, with the mean stress p a little changed, stress ratio is the essence that stress path influences the stress-strain relation of sand. When calculating the stress-strain relation using this model, the stress path is linearized in order to calculate respectively the strain on the mean stress path and equal stress ratio path. The test results accord with the theoretical prediction of pretty well, which proves the rationality of the way the model uses the function . The comparison between prediction and test results under the condition of complex stress path reflects that the model can rationally consider the influence of stress path on the stress-strain relation.

In order to investigate the effect of the initial angle of principal stress on dynamic strength and residual strain behaviors of calcareous sand under cyclic loading, a series of triaxial-and-torsional coupling cyclic shear tests on calcareous sand with a relative density of 30 % were carried out in a new universal triaxial and torsional shear apparatus of Dalian University of Technology. The test results show that the effect is marked. With the increasing of , the dynamic strength of calcareous sand decreases obviously and the rising rate of residual strain increases.

Through grain-size analysis of scrap for soft rock that was produced during test of collapsing in laboratory and test of gradual collapsing in field atmospheric condition; it was found that absorbing water and collapsing progress of soft rock is also a progress that fractal dimension of soft rock scrap change successively. When collapsing of soft rock arrived to some extent, grade of scrap of soft rock collapsed is no more change; absorbing water and collapsing of soft rock stopped; fractal dimension of scrap of soft rock collapsed incline to a critical value. The critical value opens out fractal mechanics of soft rock when it swells and collapses after absorbing water. The above-mentioned conclusion exists a guidance significance to engineering.

On the basis of analyzing the characteristic of soft soil along coastal region of Southeast Fujian Province, the relativity between static sounding values and physico-mechanical parameters of soft soil of the studied area was analyzed; and the correlation equations (empirical formula) for static sounding parameters and physico-mechanical parameters of soft soil were established. Using the empirical formula, physical-mechanical parameters along the coastal area of Southeast Fujian Province can be calculated from static sounding values. The results provide the foundation for reliability analysis of parameters of soft soil in geotechnical investigation, design and construction.

Aimed at special questions that there were many cracks in the joint segment of sluice and dam, in which the quality of clay core was disqualification, the method of filling grouting was planned to adopt. The test results showed that the grouting pressure was too low to grout slurry. Based on special circumstances there were two insert-walls in the clay core, red sandstone bam foundation, sluice-wall in the left of spillway etc., the split grouting that pour grouting at the bottom of bore and perfusion around bore, Bai’s method was adopted to treat with these hidden troubles. It showed that the slurry could not be grouted to the middle-inferior part of clay core in routine grouting pressure. By time after time tests, the conditions of split grouting was confirmed, these were the width of split on the top of dam was equal to 4cm (the criterion ordered 3cm) and the resilience proportion was larger than 80 %, the grouting pressures were 0.15-0.23MPa and 0.25-0.40MPa on the middle part and inferior part respectively. The effect of grouting is good. Concretely, inspecting results after grouting 1.5 years, are filling full slurry in dam body, nice concretion and cementation with around the earth of the slurry. The quality of clay core after grouting was improved. Up to the present, over seven years, the joint segment of sluice and dam was all right by time after time floodwaters.

Based on the method of adjusting the conductivity matrix, the composite element method is proposed to deal with the elements intersected by free surface in the analysis of unconfined seepage problems. Each composite element has two sets of the nodal hydraulic potential, one is used to interpolate the hydraulic potential in the saturated domain, another used in the domain above free surface. According to the variational principle, the governing equation is derived and is implemented in the program. With the composite element method, the problem of interpolation on free surface is well solved and the impact of the domain above free surface upon the hydraulic potential in the saturated domain is avoided. Moreover, the outflow boundary can be treated in the calculation more conveniently and more accurately. The effectiveness of the method is verified by the numerical example.

A generalized equivalent-continuum method is presented for calculating variably saturated seepage flow in fractured porous media. The model neglects fracture capillarity, sets up a threshold composite saturation value that corresponds to a prescribed pore saturation, and assume: (1) if the composite saturation in a fractured porous medium is less than the threshold saturation, water flow can take place only in the pores, and the fractures are free from water; (2) otherwise, if the composite saturation exceeds the threshold value, water enters and flows inside of the fractures. Various equivalent-continuum calculation methods are analyzed and compared. In order to illustrate the features of the proposed method, a calculation example is provided for modeling of coupled water and heat transport in variably saturated fractured rocks. The results indicate that the presented method is relatively general, and can be employed to model the main features of variably saturated seepage flow in fractured porous media.

In a representative highway loess section, the experimental investigations on treatment of loess subgrade with impaction and grind method(IGM) were conducted. In these investigation, in-situ tests(loading tests, SPTs, DPTs, CPTs) and related laboratory tests were adopted. The rule that physico-mechanical parameters of subgrade (degree of compaction, degree of density, compression and collapsibility) and depth of treatment change along with pressing number is discussed. Through investigation, it is indicated that the effective depth of once treatment can reach 1.0m and has some effect on soil layer from 1.0m to 2.0m with the treatment of subgrade of loess with IGM. Therefore the treatment of subgrade with IGM is effective, practical and has high production efficiency. And it can get a wide use in highway loess foundation engineering.

The moving features of a hard roof are studied by three-dimensional discrete element method and nonlinear dynamics; and some conclusions are obtained. The movement of hard roof at the first time is impacted and with high level of stresses; but the system of moving hard roof is an ordered steady state at the phase because value of LE1 is negative. The best chance to prevent rock burst under certain conditions is before the end of the second extracted phase, which can change the movement of hard roof from impact to periodicity. And ∑(+LEi) states that chaotic degree of the forth phase is the highest according to periodic movement of hard roof, of which the stress level is middle size. Results of the study present that system of moving hard roof is chaotic and producing alteration apart from the first impacted phase.

For the three-dimensional consolidation effect impersonal existence of roadbed and the horizontal thrust from stresses re-distribution of embankment, soil lateral deformation should not be neglected. The modification formula based on height of embankment and void ratio of roadbed for common clay and soft soil is severally given through nonlinear finite element method, which are mainly applicable to uniform or non-uniform roadbed case. It is tested that, using this method, the settlement one-dimensional calculated results can be in consideration of soil lateral displacement with engineering example. Furthermore, the modified settlement is more closed to measurement. In a way, those formulas have definite inference value in practice.

Reservoir water level rise may result in instability of a slope. Qianjiangping landslide, situated on the Three Geoges, Zigui County, Hubei Province, is a right example. Effects of reservoir water level on slope stability include the action of interspace water pressure and the weakening of strength parameters of slide interface. Using Mohr-Coulomb strength principle, effect of interspace water pressure on soil stresses is analyzed. After slope soil is soaked, the Mohr circle diminishes and moves to the left apart from the strength curve. Results of slope stability analysis show that slope stability firstly decreases and then increases due to interspace water pressure when reservoir water level rises from the foot to the top of the slope. It is also pointed out that the slope will probably lose its stability because of the disadvantageous action of interspace water pressure during the initial stage of water level rising and the weakening of strength parameters of slide interface.

Two kinds of low angle landslides, gelifluction and thaw slumping; in permafrost region of Qinghai-Tibet plateau are special slope instability patterns with freeze-thaw cycle. It is difficult to see in non-permafrost region. It is discussed in this paper that landslides mechanism of two kinds of low angle slope-soil particle transfer effect and lubrication effect with sluggish water. Based on Mohr-Coulomb strength criterion, stability analysis for thaw slumping of milepost K3035, Qinghai-Tibet highway has been carried out by applying unified safety factor formula derived with groundwater streamline parallel to slope surface to verify lubrication effect with sluggish water with active layer sliding along thick ice surface. From environmental engineering geology viewpoint, control measures based on permafrost protection principle for thaw slumping have been put forward.

There are a few paper discussed establishing constitutive models of seeping rock under tensile load until now. In this paper, micromechanics is used to establish a constitutive model of seeping rock under tensile load. The equations during establishing the constitutive models are improved because of using new extending rule for microcrack. New achievements in micromechanics are used to set up the macroscopical distortion caused by microcracks in seeping rock, and achievements in fracture mechanics are used to give out the stress intensity factors. An anisotropic constitutive model for seeping damage rock is established. The model can be applied to rock mass too.

The method to assess the critical state of slope stability is studied. There are some shortcomings in the current methods, and a new method named dynamic method is presented. In the dynamic method, the value of acceleration whether equate zero is used to assess the slope stability. Comparing with the static method, the dynamic method has clear physical meaning and the solution convergence become easier. A method to search for critical slip surfaces through search for points those shears strains are maximal is also presented. The examples have shown the reliability of the dynamic method.

Most natural soft soils have structural characteristic; so the disturbance of foundation treatment changes engineering property of soft clay ground. Mechanical parameters of disturbed soft ground cannot be measured accurately by laboratory experiment. In order to obtain calculation parameters of disturbed soft clay ground, based on in-situ test and column-expand theory, quantitative calculation methods of disturbance degree of structured soft clay ground resulted from foundation treatment are presented. The examples show that the structured soft clay ground disturbance degree resulted from the setting of PVD is about 30 %; it can be used to calculate settlement and stability of disturbed soft clay ground.

Some artificial materials were constructed according to a types of different element strength distribution, and then the inner state of the material had been discussed in line to the relationship between change of image and exterior force. By element's lightness indicating the value of inner force, breakage and acoustic emission (AE), it suggested that the AE had close relationship to the chosen critical value. Different detect critical value led to different AE mode. Usually the energy emission would become stronger when the rock mass was going to break, so it was feasible to check AE and predict rock mass' breakage by larger critical value.

This paper presents a simplified finite element method using viscoplastic strain softening mode is to capture the strain localization points in hydraulic structures, in which the bifurcation theory is adopted as the condition of onset of strain localization. The trait of this method is that the continuum elastoplastic tangent modulus needed in the bifurcation theory is just used in the judgment of localization in every time step, and has no effecton the process of viscoplasticity return mapping algorithm proposed. Compared with other methods, this model is not only based on simple theory, but also is easy to program. And numerical results show that this method is reasonable and feasible through the analysis of slope stability.

With the Wilson- numerical direct integration scheme, a 3D finite element model of the pile-soil system is established for impulse responses at the top of a concrete pipe pile. Some representative features of the calculated wave signals together with their correlation to the measurement points at the top of pile are investigated. It is shown that the three-dimensional effect of wave propagation along the pipe pile head has great influences on the local defect identification. The results are instructive for better evaluation of pile shaft defects as well as for the reasonable arrangement of transducers with the reflected wave testing.

Aimed at remedying the defect in quality inspection of dike cutoff wall, the dike cutoff quality inspection is studied and analysed by using instantaneous Rayleigh wave method. The results of Rayleigh wave curve of frequency distribution and inversion analysis is achieved about all or measuring points of jacket-well refill clay cutoff wall. The inner defects and construction depth of jacket-well refill clay cutoff wall is given. Through contrasting and analyzing indoor soil meachanics test data in situ drill hole sampling, the correlation relationship between Rayleigh wave velocity and medium dry density is achieved. The quick and efficient method is presented for controlling the quality of dike cutoff wall engineerings.

The procedure of visual post process based on double scanning beams method is proposed considering the characteristics of construction mechanics in deep foundation pit engineering. The principle and the implementation procedure of the double scanning beams method are presented. The programming for visual process class is made and the class is incorporated into the objective-oriented program for finite element analysis of deep foundation pit excavation and bracing. Through a numerical example of deep foundation pit, it is shown that the processing effect by the proposed method is perfect.

This paper presents a piled raft or piled box interaction approach which can provide a practical means of considering the effect of local softening and stiffening around the pile shaft. A test of pile group is taken as an example to illustrate the effect of variables on pile group and an approach for evaluating the effect of local softening and stiffening around pile shaft for use in an interaction analysis, is proposed .

Geosynthetic-reinforced and pile-supported (GRPS) earth platform has been emerged as an effective alternative successfully adopted worldwide to solve many geotechnical problems. This paper provides the state of the practice review of the use and design of GRPS embankments. The review includes working mechanisms, design considerations, and applications of GRPS embankment systems. The review concludes that GPRS embankment systems are most suitable for situations with a very soft soil underlain by a stiff soil layer or bedrock, new fill with certain thickness needed, rapid construction necessary, and strict total/differential settlement required. The common applications of these systems include bridge approach, roadway widening, and railroads or highways across soft soil.

The paper studies the problem of a high steep slope stability under the condition of storing water. The problem is analyzed and computed under the conditions of different storing water levels by FLAC3D software. From the results obtained we draw some conclusions: The stability of whole slope under the condition of storing water, is mainly related to the deformation stability. When the parameters determining with the fact of weathering, the productions of simulation indicated that the whole slope is stable at any water levels. The calculation of parameter sensitivity indicates that the whole slope’s stability is sensitive to rock mass parameters under condition of storing water. The whole slope is stable.

Lianyungang marine soft clay is muck and mucky soil. When the expressway was built in the district, the soft clay foundation was often treated by cement-soil piles. This marine soft clay is of high compression, lower drainage consolidation and poor stability for its roadbed. During engineering construction, the phenomena, as larger settlement deformation, crack and slide, often took place on the embankment. Based on practical project for Jiangsu marine soft clay, the composite ground of cement-soil piles is simplified into the double-layered ground. The one-dimensional consolidation of the double-layered ground is solved by means of Laplace transform for two-step loading. To get over the difficulty of solving the inversion of Laplace transform, Stehfest numerical transform is applied here. The results of calculating settlements of the double-layer consolidation theory are in agreement with the measuring settlements.

In order to apply and disseminate static cone penetration test(CPT) technology in desert investigation, a series of in-situ stimulated test and soil engineering test are carried out in big trough and medium trough under the condition of controlling relative density and moisture content in laboratory. And some indexes of Taklamakan desert sand, such as static point resistance , standard penetration test(SPT) blow count N, angle of internal friction etc. are obtained at the same time. Through analysis and linear regression, it gives two equations of - and N- and their coordination. All these are accumulated experience for ground engineering investigation of desert oil field..