Solidified saline soil in inshore with polymer-SH agent and lime has a very high compression strength, tensile strength and stability in nature and after soaking in comparison with solidified soil only by lime because soil particles were enveloped by SH agent and formed web structure between particles and in voids. Compression strength of solidified soil decreased after applying sinusoidal load, and has some attenuation with the growth of fatigue times under a preload value and constant amplitude of load. Value 30×103 times is a special starting point from which strength falls. It has been certified that SH agent has made the stable web structure in soils when two weeks and it is better when four weeks with the help of observation of SEM’ pictures. This web structure remain stable after soaking, it is obvious that SH agent’s solidifying reaction is no reversibility in soils.

Under dynamic strain control, the stress relaxation characteristics and vibration settlement of compacted loess are studied. The tests give the variation amplitude of stress relaxation according to humidity content, confining pressure, frequency and initial strain. The time of vibration settlement is very short. Vibration settlement decreases with the increasing of confining pressure and frequency, but increases with increase of humidity content. The conclusion has important theoretical significance to projects. Finally, a dynamic rheological test model is put forward based on the tests and theoretical derivation.

Malan loess is a special water content sensitive geological deposit, of which the physico-mechanical and hydraulic properties change with obvious patterns under the softening action of water. Based on the test data of a large number of Malan loess carried out in Utrecht University of Netherlands and Lanzhou city of Gansu Province with different methods; here, we study the physico-mechanical properties of Malan loess. According to the results of loess tests in laboratory and in-situ, the geotechnical properties, some laws of water sensitivity and shear strength properties of Malan loess are discussed emphatically; and some important critical indices of Malan loess are put forward.

The characteristics of soils under long-term repeated surcharge loads are discussed in detail by studying the relevant results reported in the references. The concept of introducing critical repeated stress level into the Carter Model is expounded based on the critical state soil mechanics; and the Carter Model is modified. The modified Carter Model can reflect reasonably the main characteristics of soils under long-term repeated surcharge loads. Then, the soil and pile foundation interaction under long-term repeated loading is analyzed in detail using the plane strain FEM program. In the program, the characteristics of soils under long-term repeated surcharge loads are simulated by the modified Carter Model. The law of settlements and displacements of soils and piles under long-term repeated loading is discussed; then the influences of several factors such as the magnitude of θ, critical repeated stress level and pile stiffness, etc., are discussed. Finally, some useful conclusions are drawn.

By putting some amount of cement into soil sample, natural structured soil with macro-pores is simulated. Based on the compressive tests of different stress paths, the initially yielding curve is confirmed according to the yielding stresses of a certain stress paths, as well as the direction of the increment of plastic strain after yielding. Furthermore the hardening law is presented in accordance with the result of the triaxial drained tests. An elastoplastic softening model which can simulate the effect of the soil structure is proposed. In addition, the model is verified by the test data.

The objective of this paper is to present a theoretical evaluation of the capabilities of low strain integrity tests in estimating the pile length and integrity of PCC pile, a type of large diameter thin-wall cast-in-place concrete pile. One-dimensional and three-dimensional finite element modelling are performed to gain an understanding of the dynamic response of intact and defective PCC pile subjected to impulse loads. The three-dimensional effects in low strain integrity test of PCC pile are studied in detail. The result shows that the impact response of a PCC pile is affected by bending vibration, longitudinal vibration and waves reflected between the side boundaries at the surface of pile top. Based on the numerical results, suggested guidelines for selection of the locations of the hammer impact point and the recording point and test results interpretation of this new type of pile are given.

The mathematical model of deformation and failure of rock (concrete) is presented based on the phenomena that projectile penetrates into rock (concrete), considering the compressibility of the target material. The resistance of projectile in the process of penetration has been obtained. The motion equation of projectile is gained according to the Newton’s law of motion. The parameters and penetration depth of penetration are obtained; the equation is solved by using increment method. By comparing the result of calculation with ones from the empirical formulas, the practicability and reliability of the method are proved.

Aiming at coarse-grained backfilled foundation, improvement effect of dynamic compaction has been studied by ABAUQS using geometric nonlinear three-dimensional finite element method. The plastic deformation caused by each tamping has been taken into account and the shape of the plastic zone has been identified after each drop; the parameters of soils in the plastic zone have been adjusted, which makes the base of next impact analysis. The whole process of dynamic compaction is simulated by repeating the steps mentioned above. The developments of plastic zone in different impact energies or in same impact energy but different number of drops have been obtained; and that will be used to forecast the distribution rules of reinforced zone of dynamic compaction effectively. The conclusions give some references for the practice.

The influence of moisture content, compacting energy and swelling potential grade on California bearing ratio(CBR) of expansive soils is experimentally studied. It is found that the moisture content of maximum CBR is always higher than the optimum moisture content. The difference increases as the compacting energy or swelling potential grade increase. The unsaturated soils theory is applied to explain these characteristics. The regularity is due to the different gas-water phases of expansive soils with different saturation degrees. When the saturation degree is less than the boundary saturation ratio, the CBR value increase assumes the exponential relationship along with the increment of saturation degree. But when the saturation degree is more than the boundary value, the strength property is similar with saturated soil and the CBR value is controlled by the dry density.

The method of fuzzy synthetical assessment applied to rock mass classification results in losing information of judgment, then influences veracity and reliability of the result. In allusion to the limitation, the theory of barycenter of fuzzy set is imported. Because weights of some factors is relative small, if using usual fuzzy synthetical assessment method, it will result in phenomenon of “submerge”. However, this problem does not exist now. Based on this theory, the six more important influential factors for rock mass classification such as index of rocky quality, uniaxial strength of renitency, integrated modulus of rock mass, soft modulus of rock, maximal seismic intensity and osmotic quantity of groundwater, are chosen; then the normal distribution as its membership function and the theory of the mean are used based on proportion to conform weights of the whole factors. Thus the method of rock mass fuzzy synthetical classification based on the theory of fuzzy set has been established. The calculational method of barycenter of fuzzy set of the whole factors is clarified combining a material project example. Finally, the method of rock mass fuzzy classification based on the theory of barycenter of fuzzy set is used to research the steady classification of a certain underground wall rock. Compared to the result of the method of fuzzy synthetical assessment and the actual steady instance of the wall rock, the veracity and the applicability of the textual method are validated.

By means of experiment simulating wave load in-situ, the changes of silt density and strength in the Yellow River Estuary resulted by simulating wave load were studied; by means of laboratory experiment, sea-bed silt density, strength, grains size, CET(critical erosion threshold) vs. vibration energy in the Yellow River Estuary were studied. The results show that due to wave vibration, the silt properties and CET change by wave action in the Yellow River Estuary; the CET is not only in relation to the density, grains size and shear strength, but the energy of vibration load; CET empirical equation could not apply to experiment values.

In coastal areas, the durability of stabilized saline soils as roadbed fillings directly influences the performance of roadbed because of the negative properties of saline soils. Accordingly, water stability and freeze-thaw resistance of stabilized saline soils are studied. The results of the tests indicate that the coastal saline soils stabilized by lime, cement and SH present good water stability and freeze-thaw resistance, so as to meet the requirements of highway construction in coastal areas.

The traditional calculating method of composite modulus is based on the assumption of the displacement compatibility between the flexible columns and the surrounding soil. However, case histories of embankment on ground improved by flexible columns revealed that the magnitude of the settlement of surrounding soil is often larger than that of flexible columns. The traditional composite modulus method may under-estimate the settlement of composite foundation under embankment. A two dimension finite element method (FEM) is adopted to capture the displacement incompatibility between the flexible columns and the surrounding soil under embankment and to investigate the factors influencing the settlement of composite foundation. The composite modulus of reinforced zone is back-analyzed by the layer-wise summation method. Comparison of the deformation of substratum before and after flexible columns installation yields the modified calculating method for settlement of substratum. Hence, the FEM is related with the layer-wise summation method. A practical calculating method of settlement of reinforced zone and substratum is put forward, respectively. A case study is also presented for verifying the validity of the proposed method.

The anchored crane beam is used in the underground power house of Xiaowan Hydropower Station in which the generator room, one of the biggest rooms under construction, is 28.3 m in width and 79.88 m in height. Two faults with width ranging from 0.5 to 8.5 m and in high dip angle cross the generator room and the concrete crane beam. Therefore, the stability of the rock-bolted crane girder needs to be studied before the construction. This paper introduces the in situ model test that is carried out in the draft-tube gate room with the similar engineering geology condition. The setup of the monitoring instrument and the process of loading are included. The monitoring data are carefully analyzed; and the model test results demonstrate that the anchored crane beam can work at full capacity and its stability is guaranteed.

According to the current calculating models of the retaining structure with double-row piles that based on the method of elastic reaction, finite difference method programs are developed respectively. A case study is introduced. The differences among the analyzing results by those different models are compared. Based on observation data, the most reasonable model is presented; and some influencing factors have been analyzed. The conclusions are to be very useful for optimum design of retaining structures with double-row piles.

A low frequency alternating current resistance instrument is developed for measuring the resistivity of the contaminated soil. The contaminated soils were sampled at the industry areas of Nanjing. With the instrument, the resistivity varying with the temperature is mensurated for the contaminated soil in Nanjing. The testing results show that the resistivity of the contaminated soil reduces with the temperature hoisting. It is a good logarithm relation between the resistivity and the temperature. The best ideal revising temperature method is presented base on the Keller and Froschnecht method and the Campbell method. At the same time, the rivising formula is deduced. The experiment results show that the method is more better than the Keller and Frischnecht method and the Campbell method for the contaminated soil.

A mining construction method being aimed at Beijing region geological condition is brought forward for connecting tunnels based on two shield tunnels. Firstly, part of the shield segments in this maximal connecting tunnel section is taken off and a construction traverse channel is built. Secondly, each part of the connecting tunnel is constructed by regarding the traverse channel as a construction working face. Finally, A numerical simulation with FLAC software is adopted to probe surface subsidence and stratum plastic region distribution after the shield segments being disassembled and the tunnel cross-section being widened. The result indicates that the connecting tunnel between two shield tunnels can be constructed by using mining method; and the construction method is doable to Beijing region geological condition.

The interaction between the earth berm and the retaining structure is analyzed. A simplified method is proposed to consider the effect of earth berm on the retaining pile based on the principle of elastic-reaction method. Calculating results show that with the same earth berm height, the displacement and bending moment of retaining pile can be reduced with the decrease of grade of earth berm or the increase of width of earth berm. But finally they will remain constant when certain grade of earth berm or width of earth berm is reached. The soil condition of earth berm also plays an important role for earth berm to reduce the displacement and bending moment of retaining pile. Well dewatering before excavation, protection of earth berm from being disturbed during excavation and prevention of earth berm from rain during and after excavation are important for earth berm to work . The earth berm can be treated with grouting or DMM when necessary. Case histories show that the results obtained by the suggested method agree fairly well with the field measured data. The application of earth berm in a large excavation project, where horizontal supporting system is no longer necessary, can save considerable cost and reduce construction period.

Based on the load tests of 8 large diameter belled piers and 2 friction piles, the vertical bearing behavior of the belled pier in non-collapsing loess-like soil is studied. The result shows that if other conditions are the same, the bearing capacity of belled pier (kN) increases and the end resistance decreases as the increase of the belled diameter. When both belled diameter (D) and shaft diameter (d) remain constants, the total ultimate side resistance enhances with L/d increasing. When the shaft diameter (d) is changeless, the bearing capacity of belled pier changes irregularly with L/D increasing; the percentage of total end resistance (greater than equal-diameter pile) decreases; the average ultimate side resistance (smaller than equal-diameter pile) increases; but better bearing behavior occurs as L/D=3. If the shaft diameter and the length of belled pier in soil are the same with the friction pile, the bearing capacity of the former is greater than the latter; and the settlement is smaller than the latter.

Based on the mechanism analysis, a new simplified analytical method for the pile-soil-cap interaction is proposed. According to the static loading test results, the single pile settlement at a given loading can be determined. Assuming the soil deformation between the cap and pile toe is equal to the single pile settlement, the cap shared loading can be determined conveniently at a given single pile loading. The foundation settlement is produced by the soil deformation between the cap and pile toe and by the soil compression caused by the loading of piles and cap below the pile toe. An example of the proposed method is presented; and the comparison with field measurements shows that the proposed method is satisfactory.

The in-situ monitoring data of the surrounding rock displacements reflect the changing of mechanical situation of surrounding rock-supporting system. To overcome the excessive learning problem of ANN, a new method of PSO LS_SVM to forecast the nonlinear displacements of surrounding rock in underground engineering is presented based on monitoring data. Particle swarm optimization is used to choose the parameters of support vector machine, which can avoid the man-made blindness and enhance the efficiency and capability of forecasting. The method can rolling forecast the surrounding rock deformations based on monitoring data, in order to adjust the supporting schemes dynamically and ensure the stability of the cavern. It is used to forecast the surrounding rock convergent deformations of Qingjiang Shuibuya Underground Powerhouse; and it is shown that the method is feasible and precise.

According to the excavation style and gradually adjusting of the stress after excavation in the tunnel, some typical sections are chosen to numerically analyze and forecast the status of rockburst in the whole calculational scope. According to the calculational result, some conclusions can be drawn as follows: the larger of the stress releasing coefficient has become, the area and the grade of rockburst would increase. For effectively avoiding or reducing the occurring of rockburst, the most prime support times for the different areas are given by analyzing the measuring data in-situ in this tunnel.

Slope deformation is a complex systematic process. Single point model named GM(1,1) can’t consider correlation of the deformation between the discrete monitoring points. The method of determining dynamic weight is presented; and the new weighted multi-point grey model named WM-GM(1,1) forecasting the slope deformation is established by analyzing the shortcoming of GM(1,1) which can’t acquire the appropriate background value. A case study based on the Matlab program shows that the forecast result of WM-GM(1,1) is more precise than that of the GM(1.1).

Anchoring is an important reinforcement in the geotechnical engineering. At the same time, the shotcreting is always indispensable for an anchoring engineering; so a reasonable thickness of the shotcrete and an anchoring parameter are very important for designing reinforcement engineering. Based on the theory of plate bending and considering the interaction of the shotcrete and anchor, it is concluded that the S-shape of the steel net is the most suitable. For example, based on the finite difference simulation of FLAC, the mechanism and effectiveness of the shotcrete in the reinforced earth retaining wall has been studied; the result shows that the shotcrete is effective in controlling the surface displacement of the wall, in deducing the plastic failure of the wall foot, in reducing the lose of the prestress of the anchors, and in improving the effectiveness of the reinforcement. At the same time, the study on the thickness of shotcrete indicates the reasonable shotcrete thickness should considering both the rigidity and pliability properties. This study will be an important reference in designing the thickness of shotcrete in the anchoring reinforcement.

The failures of rock masses are often resulted by sliding or extension of discontinuities. Based on the idea of effective shearing stress, the viewpoint of activation of surface discontinuities is put forward. Activated depths of surface discontinuities which surround a tunnel with circular cross-section are analyzed. Results demonstrate that the activated depths of discontinuities are influenced by their inclinations and shearing strengths; and shearing strength plays a very important role in them. Discontinuities with same inclinations result different activation depths at different zones around a tunnel. Fracture mechanics theories are employed to analyze the growth of wing cracks of surface discontinuities. It implies that the deepest possible location where a wing crack can initiate is just the place of critical activation point. So the possible maximum depth of disturbed zone surrounding a tunnel is just the activated depth of discontinuities.

The optimization methods including schemes of the supporting system and the detailed calculation and design of the selected program for deep foundation pit, are studied. Using multi-objective decision making fuzzy set analysis and analytical hierarchy process, the optimized project of the retaining system that is of the multiple attribute and fuzzy property is selected. Through the selection of decision variables, objective function, constraint condition (i.e. strength, size, displacement etc.) and optimization algorithm, the detailed structure of the selected program can be optimized in order to minimize the cost of construction. By the software Matlab 6.5, it is easy to solve this minimized value of nonlinear constraint minimization value. A practical example study shows that there is better effect on both selecting the retaining program and deciding the detailed structure.

As Qikou 17-2 platform with bucket foundation and Bohai 8th self-elevating drilling ship for example, it was simulated by three steps for the extracting of pile shoe of drilling ship by using general purpose finite element program ANSYS, using 3D 8-node element and Drucker-Prager elastoplastic stress-strain theory. When the distance between pile shoe and bucket was certain, considering the sensitivity of soil parameters, three-dimensional finite element analysis of the influence on foundation strength of bucket foundation during pile pulling was carried out. It is shown that the effect on ground bearing capacity of platform caused by pile pulling of drilling ship is reducing with the decreasing of relative stiffness and the increasing of internal friction angle and cohesive strength; among natural parameters of foundation soil, as far as the effect on ground bearing capacity of bucket edge soil due to changes of elastic modulus, internal friction angle and cohesive strength is concerned; the effects regularity of the frontal two parts are more obvious than that of the latter one.

The thrust wall is a very important component of rectangular shaft; its stress and strain are both fairly complex when it suffered the thrust of pipe jacking. How to make certain the thrust force, which is transmitted from internal lining of working shaft to external soil mass, is quite significant; how much will the soil pre-deformation affect, and these results directly affect the calculation accuracy of retaining structure and internal lining of working shaft. By using numerical modeling analysis method, the thrust force transmission pattern is found; and the reaction distribution in the depth and width direction of the thrust wall is calculated; then the internal forces of each components of the thrust wall are ascertained on the basis of known reaction distribution analysis. This paper offers references for calculating pipe jacking thrust wall according to rational simplification and approximate hypothesis.

There are lots of nonlinear analysis methods on studying piles. Among these methods, the load transfer function method is an important one. And the complexity of problem results in many function forms that can be used in some range. The generalized load transfer function is a universal function form that can reflect all functions reported in the literature. The generalized load transfer function can be transformed to other forms by adding a parameter. At the same time, it can reflect the softening effect. Based on realizing the mechanics parameters of soil in site, the adoption of this function can decrease number of trial piles. Therefore, it can make the project to be more economic.

Based on nonlinear finite element calculation, the influence of size effect of pile on load-bearing behaviour of rock-socketed pile is analyzed. The results show that the rock-socketed depth-diameter ratio decreases with increasing diameter of pile while other conditions are invariable, bearing capacity of pile takes on increscent trend due to chiefly bearing pressure of pile tip enhancing. Additionally, socketed depth influences the bearing properties, the shorter socketed depth, the more strength load-bearing of pile tip. So the bearing capacity can be enchanced by enlarging pile diameter in course of design.

Micromechanics is used in the study of mechanics character of slate. A constitutive model of slate under compression and seepage is established. The process of swelling distortion caused by shearing and seepage are considered for the equations during establishing the constitutive models. The frictional sliding and mode-Ⅱ self-similar growth of closed microcracks under compression and their influences on the mechanical properties of rock are studied in detail. The model is validated by experiment.

Considering the influence of lateral deformation of subgrade, bilinear settlement prediction model was advised to adopt. This model includes time series, linear regression and bilinear items. In order to study the time-dependent characteristics of parameters in the model, settlement prediction fell into parameters prediction and settlement prediction based on the former one. Multi-layer recursive method was adopted to calculate time-dependent parameters, whose tendency of movement was further analyzed. Prediction of settlement was obtained after calculating prediction values of parameters. Case study demonstrates that the bilinear dynamic prediction model is worth applying widely for well showing settlement characteristics of subgrade and having a higher precision.

Debris flow is the gravity flow of water, clay, granular and rock mixtures and often triggered by torrential rains in mountainous areas. It is a catastrophic disaster that consists of grain-fluid mixtures and moves rapidly across three-dimensional terrain. Most debris flows move downslope as fluids. To predict the runout distance and extent of the hazard area of rainfall-induced debris flows, we proposed a depth-averaged two-dimensional mathematical model, in which the debris and water mixture is assumed to be uniform continuous, incompressible, unsteady Newtonian turbulence fluid. Based on mass balance equation and Navier-Stokes equations, the mathematical model is derived using the method of depth-integrated equations. The finite difference method is necessary to solve the all equations. Based on GIS, the two-dimensional mathematical model of debris flow can be used to estimate the flow range, the potentially dangerous homes and roads for hazard and risk analysis.

Based on the mesh regeneration and mapping of field variables, a large deformation finite element model was developed. The uplift capacities of circular plate anchors in immediate break away case and no break away case were investigated using this model. It is assumed the anchors are buried horizontally in uniform clay. Compared with small strain finite element calculation, large deformation analysis overcomes the severe mesh distortion of soils around the plate anchor, which makes it possible to describe the variation of uplift capacity during the whole pulling-up process. According to several numerical examples under immediate break away condition, the effects of anchor roughness and overburden pressure on uplift capacity are studied. It is found as considering soil weight, uplift capacity of deep anchor is lower than the sum of corresponding capacity in weightless soil and the overburden pressure, and the upper limit is the capacity under no break away condition. It is shown that the soil weight puts slight effect on no-break away-capacity. The relationship between no-break away-capacity and initial embedment of anchor is offered.

A new strength criterion was deduced based on the existed strength criteria for cohesionless soil such as the SMP model and the Lade model. It properly reflects the influence of the single principal stress on the mobile surface instead of just being restricted within the influence of the intermediate principal stress. The new criterion can fit the experimental data obtained by the previous study very well and seems to be superior to the traditional ones.

Surcharge preloading is an effective method of foundation treatment; and its effect can be reflected from the ground settlement caused by load of building after treatment. The value of the settlement is related to surcharge ratio and consolidation degree when surcharge is unloaded. There is still lack of simple and effective computational model about average degree of consolidation which ground should achieve before surcharge is unloaded (i.e. the problem of unloading control).A two-components consolidation model, in which nonlinear elastoplastic stress-strain relation of soil skeleton is considered, is put forward based on the principle of surcharge preloading and test curve. The consolidation differential equation of the model is derived. The result of calculation based on the model is more reasonable compared with traditional theories of unloading control. And the effects of permeability coefficient and ratio between elastic and plastic strains of soil skeleton on unloading control are discussed.

Because of the solution method unreasonable,the settlement calculation precision for the dry jet mixing pile(DJMP) is unconvincing. Based on the load transfer behavior and the characteristic of DJMP, using Boussinesq solution and Mindlin solution, the additional stress is calculated. Different calculation methods are used to analyse the stress distributing characteristic for stabilized layer and the underlying soft layer. The correlative formula is derived. Calculation result shows that the Boussinesq－Mindlin united solution method is reasonable and feasible.

As analyzing the interaction of water-soil coupling field, we take soil mass as elastoplastic material. Based on nonlinear constitutive relation, the finite element equation of rock considering seepage field can be obtained. The 3-D water-soil coupling mathematical model about dewatering of foundation pit is established; and the different geological model such as groundwater bearing bed, artesian aquifer water bearing bed and exceed flow alimentation artesian aquifer water bearing bed and every engineering condition such as embedded depth of filter tube and depth of stop water heavy curtain are calculated and treated. Taking the International Stock Exchange Hotel in Wuhan for example, the dewatering process of foundation pit is calculated by 3D finite elements. The three-dimension numerical simulation method can be applied to model impervious curtain, anisotropy and non-homogeneous, confined-unconfined water in practical engineering conditions and geological model, which are hard to solve in analytical method.

Considering that there is little study about shaft resistance transfer behavior of overlength pile and the theory is based on short pile yet, shaft load transfer function of overlength single pile which considering depth influence is presented. Moreover, load transfer method and FEM are combined. The load transfer function mentioned above is used to simulate rule of shaft resistance of single pile. Method of inversion is used to obtain parameters of shaft load transfer function. Example shows that the results that depth effect is considered is greater than the one that depth effect is not considered and the first one is closer to the test result. Considering depth effect is reasonable and necessary.

Rock-soil aggregate mixture come from excavation is broadly used as filling in roadbed and foundation for its high density and convenience construction; affected by geology, rock-soil ratio, grain size distribution and other factors, the mechanical behavior of rock-soil aggregate mixture puts up obviously nonlinearity; additionally its intensity index can’t detect by routine tests, so that roadbeds or foundations filled with rock-soil aggregate mixture always occur a rather large differential settlement or slump, severely affecting the function of superstructure. To disclose its intensity character and variety rules with influencing factors, this study improved large scale direct-shear test, developed a large scale direct-shear test system, using this improved large scale direct-shear test system, carried out shear test on different kinds of rock-soil aggregate mixtures. The results show that the shear destroying rule of the mixture did not obey Coulomb law on high stress condition; its intensity should be discounted. Test results show the variety tendency of intensity index with influencing factors; the elementary rules of the friction angle varied with apiece influence factor are established. Test results also show that the character of native rock and rock-soil ratio of mixture have relatively bigger influence to the intensity index; the friction angle of hard rock mixture general is greater than that of soft rock mixture; rock-soil ratio has little influence on the intensity while the rock-soil ratio less than 30 %; the intensity of mixture increases with the increment of rock-soil ratio as parabolic curve, generally reach peak value at the ratio about 70 %.

The double-arch tunnel is built usually by the full-face method under the condition of surrounding rock masses grade II and grade III. Vibration of blasting has been simulated and analyzed by three-dimensional numerical simulation during construction process of the double-arch tunnel; and the influence of blasting vibration on the middle wall of the double-arch tunnel caused by the rear tunnel is studied. The result indicates that the blasting of the rear tunnel creates much effect on the middle wall of the double-arch tunnel; there is a great need for protection to reduce disturbance of middle wall caused by blasting vibration; and temporary support will be destroyed.

In recent years, the certain red mud dam appears cracking, water penetration and leakage of red mud. The side slope of dam body basically is on the critical stability state. When triggered by some disadvantageous factors, the dam may remain widespread landslide. Based on fully studying geological conditions and frameworks of soil layers in a heap of dam areas, existing condition and formation cause of cracking, deformation course and destructive trend and principal influencing factor of stability and with a plentiful numerical experimentation and simulation analyses, a full-scale plan for reinforcement including draining, improving soil property of slide zone, cutting slope for reducing load, pressing slope base inversely ,reinforced support and slope protection with suspension net by spouting, is put forward. The simulation analysis for reinforcement by construction course proves that the comprehensive plan is scientific and reasonable.