Applied Mechanics and Materials Vols. 405-408

Abstract: Landslide instability hasplenty of influential factors. However, shown by considerable practical casesof landslide instability, rainfall is considered to be a major element leadingto landslide. Rainfall increases the weight of slope mass, while reduces itsstrength parameter. Rainfall may as well create water pressure inside theslope, while water pressure has significant influence on landslide stability.In the paper, finite difference software FLAC^3D is adopted toperform a numerical simulation on practical landslide, with the objective tofigure out the safety coefficient and stress-strain property of landslide undernatural state and waterlogged state, to analyze the possibility of landsliderenewal and to provide reference for researches on similar landslides in thearea.

Abstract: The characters, research and utilization of Ground Granulated Blast Slag are presented in this paper. Some current use of GGBS in soft soil treatment is introduced. In addition, the paper also focuses on the comparative analysis of the effects of GGBS and Lime Stabilization which is the traditional method in soft soil treatment on compaction characteristics & Atterberg limits. Next, the strength mechanism of GGBS, a kind of Soli Stabilizer applied in soft soil treatment, is mainly explained and also the validity of GGBS has been proved. All of these indicate that GGBS has the superiority of social benefit, economic benefit and environmental benefit in soft soil treatment.

Abstract: The thawing settlement related problems in 109^th national highway in Qinghai province were analyzed in this paper, experiment tests were conducted to investigate the behavior of subgrade under dynamic loading during thawing, a numerical simulation for the tests were also conducted. Both the tested and simulated results were analyzed and summarized.

Abstract: The study derives the closed-form solutions of the long-term elastic consolidation subjected to the fluid line sink in a homogeneous isotropic elastic half space aquifer. The Hankel transform in a cylindrical coordinate system is employed to develop the analytical elastic solutions. Derivations of governing equations are based on the mathematical model of Biots theory of poro-mechanics, and the half space aquifer is modelled as a saturated porous stratum which is bounded by a horizontal surface. The total stresses of the aquifer obey Newtons second law and Hookes law. Besides, the mass conservation and Darcys law are introduced to formulate the governing equations of pore fluid flow. The software Mathematica is used to complete the symbolic integrations and obtain the closed-form solutions. The solutions can be applied in dewatering operations of compressible aquifer.

Abstract: Triaxial consolidation undrained shear tests were carried out on both undisturbed and reconstituted samples of natural silty clay to investigate their undrained shear strength characteristics. Test results suggest that the strength envelope of the undisturbed sample is composed by two straight lines, which is different from that of the strength envelopes of reconstituted samples showing a straight line through the origin. Undrained shear strength of undisturbed samples are larger than corresponding reconstituted samples due to the resistance of soil structure in the pre-yield stress state. In the post-yield stress state, however, strength envelope of the undisturbed sample lies among the reconstituted samples with different initial water contents. Undrained shear strength for undisturbed samples in the post-yield stress state and reconstituted samples can be well correlated with the water content under different confining stress, which implies that undrained shear strength mainly depends on the current water content.

Abstract: In some cases, structures are built on or near aslope. The ultimate bearing capacity of the foundations for these structures issignificantly affected by the presence of the slope. In this paper, the ultimate bearing capacity of footings near slopes is investigated by the finiteelement method. Consideration is given to the effect of slope angle, height ofslope, the distance from the edge of the slope to the footing, soil propertiesand the interaction between the soil and footing. Conclusions are drawn: Ingeneral, the dimensionless bearing capacity q_u/γB increases with theincrease of the ratio c_u/γB, the increase of L/B, and decrease ofthe slope angle β. Thecurves describing the relationship between c_u/γB and q_u/γBcan be characterized using three main properties, namely a linear section, anon-linear section, and zero bearing capacity point. Within the linear section,local bearing capacity failure contained to within the face of the slope; theheight of the slope does not influence the bearing capacity. In the non-linearsection, the curves of the relation (c_u/γB, q_u/γB) isgoverned by overall slope failure.

Abstract: Based on the assumption of the improved groundwater pressure distribution, the calculation expression of anti-sliding stability factor for typical water-saturated rock slope is deduced through limit equilibrium method. Considering the combined effect of slope overload, seismic load, anchoring effect, ice frost, slip surface drag force and slope groundwater pressure, the comparative analysis of typical rock slope sliding stability under waterless and saturated conditions shows that, the outflow joint blocking and the groundwater levels rising have obvious adverse effects on the anti-sliding stability of rock slope. Figures about the relationship of stability factors and geometric factors were drawn and the anti-sliding stability factor can be directly obtained from these figures. All would be the references for the similar engineering projects.

Abstract: Landslide of expansive soil slope is a serious disease and difficult to correct in highway construction. And the mechanism of landslide of expensive soil cutting slope is complex, so the traditional slope analysis method is unable to analyze it to obtain the reasonable explanation. But the numeric analytic method can obtain the stress, strain and plastic zone of side slope analysis the distortion process of earth slope and the latent sliding plane reasonably, adopt the safety factors to evaluate the slope stability, The paper based on ANSYS and adopts the nonlinear and elastoplasticity model of soil, and use the theory of the shear strength reduction method with FEM to analysis the rule of NanYou road expansive soil landslide. Keywords:Expensive soil landslide of cutting slope swelling force FEM

Abstract: To find the influence of the layout of punning position in dynamic compaction for loess, four model tests are performed, which equal in the tamping energy but differ in the layout of punning position. In model tests the settlement, the dry density and the shear strength parameters of the soil samples are measured and analysis of the effects of different test plans is made. The test results manifested that the decrease of the distance between the pounding points might result in an increment of the settlement, the dry density and the cohesive strength but not the angle of internal friction. And from the comparison of the test results, a more efficient layout of punning position is given.

Abstract: Seepage properties of fractured rock mass are of prime importance for hydraulic engineering and accurate description of rock fracture geometry parameters is an important and basic task in rock hydraulics. In this paper, an improved K-means clustering algorithm for structural plane of fractured rock mass was first brought forward and the corresponding Matlab program for discontinuity orientations partitioning was compiled and then used in the fitting analysis of dominant orientations of certain dam foundation rock mass. On this basis, combining calculation formulas of multi-group fractures, the permeability tensor and principle value was calculated for the actual dam foundation. The results provide a theoretical and computational reference for other similar projects.