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Using ABAQUS software analyzed the dynamic response of foundation pit supporting structure under vehicle loads. The vehicle load was simplified as a half-wave sinusoidal load, in order to analyze the influence of internal force and displacement of pile-anchor supporting structure under the vehicle loads, the position of half-wave sinusoidal load and the size of radian frequency were considered. Loading location away from the supporting structure is more nearly and the displacement value of support piles is greater, the greater the axial force of the bolt; with the increasing of radian frequency, the horizontal displacement value of supporting piles increased, on the contrary, the axial force of bolt reduced. A practical engineering was studied here. analysis of the monitoring data and compared with the numerical results, the analysis showed that the experimental results and numerical results are in good agreement, and the numerical method can be used as an effective means of research. The conclusion of the study has significance on engineering practice.

Large amount of loose deposits and potential geo-hazards were formed by Wenchuan earthquake , which would be transformed into collapses, landslide and debris flows under the condition of rainfall or aftershock. The paper divides influence factors into triggering factors and background factors, and constitutes susceptibility forecast system for geo-hazard based on factors in parallel or series. The background system contains stratum, distance to river, relief, slope and aspect of slope. And the triggering system includes distance to seismic fault and rainfall . The paper applies and verifies the system to forecast the susceptibility of geo-hazard in study area, and the result shows that 52 small watersheds are in extremely high and high states accounting for 37.68% in 138 small watersheds. According to the statistics of 23 geo-hazards from field investigation, 13 geo-hazards are in extremely high risk grade of susceptibility and 10 geo-hazards are in high risk grade of susceptibility , which shows that the result of susceptibility forecast of geo-hazard is reasonable. © (2013) Trans Tech Publications, Switzerland.

Abundant landslides were triggered by Wenchuan earthquake. The paper mapped 4722 earthquake-induced landslides and used Geographic Information System to finish the statistical data about the occurrence of landslides correlating with environmental factors including distance from middle faults, lithology, altitude, river, and slope steepness. Because the seismic energy released along the middle faults and the attenuation of energy was obvious in minor axis, the zonal distribution of landslides was consistent with strike of middle faults and about 64.42% of landslides occurred within 20 km from middle faults of Longmenshan. As the middle faults and front faults both belonged to thrust faults, the impact of earthquake in hanging wall was higher than that in footwall. Therefore, the density of landslide in hanging wall of middle faults was obviously higher than that in footwall. As the release of seismic energy was restricted by landform and river, landslides were concentrative and consistent with the spatial distribution of rivers in the mountainous terrain. The scale effect of seismic acceleration was so intense in top of mountain with high difference in elevation along river that the origin of most landslides were in upside of slope. About 99.43% of landslides distributed in area where the seismic intensity was more than VII.

Under cyclic loading of concrete structures, fatigue failure is the main failure modes of fatigue, which has become the fatigue design of concrete structure must be considered, then the concrete fatigue studies must clarify the fatigue life of concrete under different survival curve S-N curve. Based on the statistics of the two parameter Weibull distribution theory, obtain the concrete under different survival rates of fatigue life distribution, namely to improve survival, reduce the fatigue life; stress level is reduced, the fatigue life is increased; and has set up more than 50% under different survival rates of concrete fatigue equation.

This is the first introduction of multimode system theory for risk assessment of earthquake-induced landslide. The paper defines the small watershed as multimode system which included triggering system and environmental system, through studying the relationship between multimode system and risk assessment of earthquake-induced landslide. Then the paper evaluates the risk of earthquake-induced landslide in 138 small watersheds with the multimode system, and verifies the result with the landslide data from interpretation of unmanned plane image. The result indicates 67.01% area of landslide in extremely high and high hazard levels. The structure and function of risk assessment model of multimode system is consistent with the formation mechanism of earthquake-induced landslide, which could avoid and decrease the artificial and random in dividing the evaluation index and risk degree of landslide.

The deformation and failure induced by Wenchuan earthquake between bedding and anti-dip slope existence very big difference. The number and size of the bedding slope deformation and failure are much more than the anti-dip slope according to the investigation and analysis. In order to analyze the layered structure affect on seismic dynamic response of rock Slope. As bedding and anti-dip slope is the study object and the seismic dynamic responses of different layered structure slope have been studied by using ANSYS finite element method in this study. Analysis shows that slope as a structure, the internal structure different lead to the slope seismic dynamic response is also different. The bedding and anti-dip slope seismic dynamic response is discontinuous or mutations in the slope as layered structure interface the boundary. And the seismic dynamic stress, displacement and acceleration of the bedding slope are always greater than the anti-dip slope. The seismic response characteristics further increased the deformation and failure probability of bedding slope. The results consistent with the investigation conclusion that the stability of anti-dip better than the anti-dip slope

Wenchuan earthquak induced a large number of mountain hazards. Through the survey found that manual excavation slopes tend to become concentrated area of mountain disaster, it’s indicate that the effect of excavation damage on the slope deformation and failure under seismic load is very obvious. Soil slope deformation as one types of mountain hazards induced by Wenchuan earthquake, and it’s also seriously affected by excavation damage. In this paper, as Shui Caoping landslide for example, using the finite element method to simulate the landslide and analysis the overall stability and the local deformation and failure of slope affected by the excavation damage. Analysis shows that the local damage is significantly induced by excavation, and resulting in vertical stress and plastic strain increased in the local of slope near the excavation face. While excavating also has the role of unloading. The results basic agreement with the characteristics of the slope deformation and failure induced by Wenchuan earthquake.

Wenchuan earthquak induced a large number of mountain hazards. Through the survey found that manual excavation slopes tend to become concentrated area of mountain disaster, it’s indicate that the effect of excavation damage on the slope deformation and failure under seismic load is very obvious. Anti-dumping slope deformation as one types of mountain hazards induced by Wenchuan earthquake, and it’s also seriously affected by excavation damage. In this paper, as Wang Jiaping landslide for example, using the finite element method to simulate the landslide and analysis the deformation and failure of slope affected by the excavation damage. Analysis shows that deformation and failure of slope is significantly induced by excavation, and resulting in displacement, stress and the between layer sliding distance increased，the between layer friction stress reduced. The results agreement with the characteristics of the anti-dumping slope deformation and failure induced by Wenchuan earthquake mainly concentrated in excavation slopes.

Acoording to the servic eability limit state, use the numerical analysis the method, using the fiinte element analysis software to the elastoplastic and the big distortion on the power solidifies in the finite element model, by using above coupled non-linear numerical approach, the dynamic response of piles and the earthquake resistance reinforcement. A computation method of raft foundation is brought foward in which many factors are considered. The method corresponds to real foundation working conditions. The results indicated as follows: Under the earthquake load function, the slope and anti-slide piles displacement response was amplified as the seismic motion propagated upwards through the slope. The greater the earthquake acceleration, the larger the deformation of the anti-slide pile. And the displacements of the pile were decreased from top to bottom. The different elevational point of the dynamic moment in the change tendency is the same. the dynamic moment to increase along with the input earthquake wave acceleration increases. There were larger differences occurring in the maximum value of resistances on the partial pile lain in stable rockmass and resistance distribution forms with different accelerations in different times. The calculation indicates that the new method may better reflect the actual locating state and sliding process of debris landslide and anti-slide piles under earthquake.

It was difficult to analyze the stability of the rock slope for its complex geological structure. Rock mass was the geological body that subjected to intense deformation and suffered damage, which was composed by rock and jointed rock mass. When the rock mass was in the high steep rock, its loading state was further complicated. First we analyzed the failure mechanism of jointed rock mass in theory, and we used Flac3d with the Mohr-Coulomb yield criterion to simulate the displacements and stresses. We built three models that included angles with level line were 25°, 45° and 65°. The results showed that, all around the joints stresses concentration occurred, the maximum compressive stress occurred at the crack tip; the final crack direction always tended to the direction of maximum compressive stress; and when the angle was bigger, before the crack expended further, the strength of rock decreased first, and destroyed first.

Volume and slope are two important factors affecting the runout distance of landslides. Field investigation on 46 landslides triggered by the Wenchuan earthquake show that there are positive linear correlations between the logarithmic values of landslide volume and travel distance. And there is also a positive linear relationship between the equivalent friction coefficient and tangent value of initial slope angle for the landslides. On the basis, we obtained an empirical-statistic equation between the horizontal and vertical travel distance, the volume and initial slope angle. This can provide a basis for prediction of earthquake-induced landslides.

The research is for the firs floods and the post-drought in Yunnan area in 2010. The strong rainfall and the hole pressure change are the red rock landslide most essential factor, so an apex post-modulus which indicates the effect of pore-water pressure on stress—strain curves transition is defined at the first. By combining with the stiffness criterion of landslide is analyzed. Consequently rainfall and other conditions changes have important effects induced landslides. It union research thinks of the elephant mountain landslide area, that red rock landslide slope body displacement and the rainfall amount relations and the slope body full water area compares and the stability of slope coefficient relations, establishes one under the strong rainfall function the red rock landslide cusp sudden change model, the quota and qualitative reveals the strong rainfall to the red rock landslide trigger action. This developed model may carry out some use full knowledge to understand the disaster mechanism and the evolutional or accumulative process of hazard factors in mountain red layer of the slope stability problem, which may mean the further to advance the technique of forecasting, it can provide important reference to the disaster prevention.

The initiation is the core issue in debris flow study, it’s the basis of debris flow disaster prevention, and the research on transformation of landslide into debris flow is fundamental in debris flow study. Transformation of landslide into debris flow was a new topic which proposed in recent years, although it contained the previous areas of landslide-debris flow, something developed, it was more emphasis on the transformation process of landslide to debris flow. This paper proposed an ideal model from practical disaster, based on Coulomb Particle Flow Theory, we used large-scale finite difference software FLAC3D to analyze. From soil mechanics, to study on excess pore water pressure and the instability mechanism of slope, we got several laws. The results showed that, (a) the maximum excess pore water pressure occurred in the lower part of gravel slope body, with the increase of external load increasing, here would be the first liquefaction area; (b) crushed gravel soil had been largely destroyed when the slope in critical state, and at the same time internal energy of particles increased, cement ability decreased. With the rock sheared, gravitation energy of rock was released, high-speed gravel slope spilled into debris.

A large number of mountain disasters were induced by Wenchuan Earthquake, and as one type of them, the deformation and failure modes of anti-dip slopes were influenced by overburden. Under the condition of no overburden, the collapse will mainly occur; while under the overburden condition, it is the shallow slump mainly occured. Taking the landslide of Wangjia Mountain in Longmenshan Town, Pengzhou City as an example, the anti-dip slopes were stimulated by using the finite element method in this study, where the influences of overburden on deformation and failure of anti-dip slopes were analyzed under the static condition with seismic load effect. The related analysis showed that significant influences of overburden existed on the deformation and failure of slopes, resulting into great increments of slope displacement, stress and sliding distance. The analytical results were consistent with the characteristics that the large-scale deformation and failure of anti-dip slopes mainly occurred on the slopes with overburden in the Wenchuan Earthquake.

Deformation instability of slope due to rain was one of the most common geological disasters. Speaking from the mechanism, the destructive action and triggering action of rainfall affected the stability of slope itself, which made the slope deform and even lead to instability. June 28, 2010, Guanling in Guizhou province a large landslide occurred which triggered by continuous heavy rainfall, it caused that in two village-groups 107 villagers were buried, all the tragedy of houses were completely destroyed. Using finite element software ANSYS to simulate the mechanical behavior of the landslide, to analyze the deformation mechanism, we got that the large landslide deformation mechanism was a complex mechanical geological process. From the analysis of interaction between soil and rock, the landslide showed complex mechanical geological features. As rainfall increased the strength of unsaturated soil and weak intercalation reduced, this strengthened the role of the slope deformation and failure. The lock-fixed section first appeared brittle fracture, then that brought shear failure to the creeping section. The interaction between lock-fixed section and creeping section was the key of slope failure.

The pile-anchor supporting structure is widely used in foundation pit engineering; then knowledge of active earth pressure on piles is very important for engineers. In this paper, based on the pseudodynamic method and considering the vehicle’s vibration characteristic, a method to calculate the earth pressure on piles under vehicle load is presented. At the same time, the constraint of anchor is simplified relation of lateral deformation of piles in present method. Effects of a wide range of parameters like rupture angle, vibration acceleration coefficient, wall friction angle, and soil friction angle on active earth pressure have been studied. Results are presented in terms of coefficients in the figures and comparison of the test data and the earth pressure calculated by M-O method and present study. The result shows that the measured earth pressure is accordant with the theoretical analysis, so the method in this paper is an effective basis for the calculation of earth pressure on piles under vehicle loads.

Micro-piles are widely used because of its own advantages, but relatively few theoretical studies about its anti-slide mechanism. Through the different pile spacing under three rows of micro pile reinforcement debris landslide indoor model experiment to study the micro-piles against sliding mechanism. The test results show that: the pile spacing of 5D, three rows of micro piles structure can produce sliding resistance of the biggest and the maximum sliding resistance. Pile been pressure and the bending moment of the piles mainly concentrated distribution within the scope of the sliding surface above 1/3 pile range and closer to the surface greater. Landslide thrust transfer coefficient 

The feature of dynamic response of highway embankment slope under the action of seismic dynamic loading is analyzed by using numerical simulation. The influenced factors of the dynamic response of roadbed slope are discussed in detail. These include dynamic characteristic of earthquake, properties of rolling soil and geometric shape of embankment slope. The distributions of amplification factor of peak acceleration, peak velocity, peak displacement and relative displacement are comprehensively analyzed under various working conditions. Some useful conclusions that the distributions of amplification factor of peak acceleration, peak velocity, peak displacement increases gradually with the raising of height. The contour of relative displacement is similar to the amplification factor of peak displacement, and the maximum displacement appears on the 2/3 location of slope, direction to the slope outside.