Applied Mechanics and Materials Vols. 580-583

Abstract: In this paper, based on the principle of gray theory, MGM(1,n) multi-variable settlement prediction model was established. Combined with specific examples of projects, settlement of rigid pile composite foundation was predicted, and the prediction results are compared with both prediction results of GM(1,1) gray model which is currently comparatively mature and the settlement observation results. The study shows that it is effective to use MGM(1,n) multivariate gray model to predict composite foundation settlement.

Abstract: Aiming at a new joint filler for pitch concrete pavement, processing it in different condition of water, determining the tensile strength through tensile experiment, analyzes the effect of adhesion performance from joint filler in water surrounding; does analysis to the adhesion performance of the recurrent tensile test in identical water surroundings.It evidenced that the new joint filler is much less affected in water surronuding than rubber modified bitumen,which is made by CARFCO inUSA,what meas that the new joint filler is much better than rubber modified bitumen on adhesion performance.

Abstract: Based on field investigation of random fractured rock mass, the sample parameters are put to statistical analysis, and 2-D fracture network model is established with probability-statistics theory and Monte-Carlo simulation technique. Finally, 2-D fracture network model is formed, which gain fracture distributed regularity in statistical sense, and is of important meaning to describe the fracture geometrical characteristics.

Abstract: Taking steel-plastic composite reinforced band (CAT) and gravelly soil as the test materials, the pullout tests of reinforced band in gravelly soil with different water contents have been carried out by the laminated shear test instrument. The interface friction characteristics between reinforced band and gravelly soil are studied, and the influences of water content on the interaction characteristics are also discussed. Results show that (1) the extraction of reinforced band is a gradual process. The anchor end began to move firstly because of the extensibility of reinforced belt itself. As interface friction gradually transfer backward by, the free end start to move onward, then displacement schedule curves of the anchor end and the free end are gradually parallel, the whole movement of reinforced belt happens immediately. (2) Pulling force and displacement curve of the pullout friction test displays obviously nonlinear characteristics. Pulling force of the reinforced band increases greatly with increasing displacement at the beginning of the test, then decrease with the increasing displacement after the peak value is reached, the force-displacement curves generally exhibit strain soften characteristics. But it present strain hardening trend under greater normal stress, and pullout frictional strength increases with the increasing normal stress. (3) The pullout friction coefficient of the interface is sensitive to water content. It decreases linearly with the increasing water content.

Abstract: The special advantages of Soundless Crack method are safety and environmental protection. Soundless Crack is widely used in stone exploitation, partly crack of brittleness materials such as rock and concrete, and backout of building in city. In these engineering, we must drill many holes for loading Soundless Cracking Agents, but the drilling cost is expensive including human cost and materials cost, at the same time need much time to drill these holes. So we hope to gain the best crack results at the minimum drillhole numbers. This paper used RFPA software to set up some models with different drillhole numbers, gained different failure process of models. Adopted different drilling plan will occur different results. We should drill more holes if we need partly crack smoothly. We can plan the number of drillholes based on our need if we can use RFPA to simulate the failure process before beginning.

Abstract: Accompanied by the substantive construction of domestic ports, the negative skin friction on pile becomes a common problem. In order to provide references for the related experiment research in the future, the designs of model experiments reported in the literatures were emphatically analyzed and compared. Compared to conventional pile model test, the model test on negative skin friction on pile needs to apply load on soil surface and it is difficult to simulate large surcharge by conventional test methods. An experimental scheme which could produce large surcharge load by conventional test conditions is given in this paper. Pile stress, displacement of pile top and layered settlement of soil was tested under different surcharge level. The depth of neutral point and the group effect of NSF are discussed.

Abstract: In geotechnical engineering, the support pattern regularly applied is continuous wall, whose high security, strong adaptability, good stability and other characteristics have been widely appraised in engineering circles. This paper use Midas to build the three-dimensional research model on varied construction stages of foundation pit, in which the foundation pit applies the scheme of combing continous wall and inner support. Further more, this paper makes estimation on the machenical stability in varied construction stages of foundation pit and use strength deduction method to analyze the stress and strain conditions of foundation pit in different working states, the results acquired from which researches have certain reference to the engineers.

Abstract: Earthquake can cause heavy casualties and property losses immediately, and induced a mass of secondary mountainous disasters such as collapse, landslide and debris flow. Collapse and landslide provide abundant incompact solid matter for movement of debris flow directly, which makes the debris flow ravines be active in a long period in the future. Taking one debris flows on Bailong River as an example. Based on the analysis of the valley features and the forming condition scientific prediction for the trend of the debris flow activities and estimates the hazards situations have been achieved.

Abstract: The soil water characteristic curve (SWCC) has been tested during the drying process. In order to define the relationship between suction, degree of saturation and void ratio, fitting models of SWCC was established. Studies have shown that the shape of SWCC of three kinds of samples (taken from Jiaohe, Gaochang and Jiuzhoutai) was similar to the inverted “S”, the relationship between water content and matric suction was inversely proportional. Under the condition of the same moisture, the matric suction of the Jiaohe and Gaochang samples were greater than the Jiuzhoutai samples, and the changes of pore water pressures showed the same trend. The degree of saturation began to decrease when the water content reduced to the air entry value. When the degree of saturation was greater than 90%, the volume of soil samples contracted significantly, and when saturation is below 80%, volume shrinkage stopped.

Abstract: The research uses the method of three-dimensional finite element analysis combined with the actual project application to study the slope reinforced by anti-slide pile. The research analyses the influence of reinforcement that the anti-slide exert on the soil and shows the changes of the sliding surface properties by establishing the finite element numerical model. The conclusion can be made that the ABAQUS finite element method is visual and practical. The study is of great benefit to the actual engineering.