Applied Mechanics and Materials Vols. 275-277

Abstract: We have found a way of a pipeline transportation of soft clay in order to overcome the difficulties to transport soft clay so that the long distance transportation of soft clay becomes true in Engineering. By analyzing the properties of soft clay and pipeline transportation, the rules of decreasing energy through the pipeline transportation, and the characters of flow field with gas, liquid and mud, we have obtained a mathematical model for the pipeline transportation of soft clay. The model not only builds up a theory for the non-continuous soft clay column pipeline transportation techniques but also leads to further developments and wider applications of the pipeline transportation of soft clay.

Abstract: The main purpose of the gravity dam stability analysis is to examine the stability safety in all possible load combination cases. Combined with the engineering example, the method of modeling , loading and analysis for the gravity dam by ansys is introduced in this paper, then the limit equilibrium method and the strength reserve method are adopt to calculate the safety factor under two conditions. The results indicate that the two safety factors which are calculated under two conditions can all satisfy the standard requirement; it is reasonable to analyze the gravity dam stability through two methods.

Abstract: To construct high grade road in the mountain area will meet the high rock filled embankment inevitably, the high rock filled embankment has become one important temp of the roadbed structure. This paper based on nonlinear elastic-plastic finite element method, by means of numerical simulation, under the stress of weight, external load, strain and displacement variation analysis, which can provide more reliable parameters for the design of High-filling embankment.

Abstract: Fissure is one of the most important characteristics in expansive soil. It’s an important factor affecting slope stability in the expansive soil area. With the study of expansive soils typical channel slope fissured characters in the South-to-North Water Diversion Project, different impaction on slope stability such as location and inclination of the fissure are analyzed. By using the limit equilibrium method, the stability of expansive soil slope is analyzed; the most adverse condition of expansive soil slope is concluded. Then anti-slippery pile reinforcement in expansive soil channel slope is studied by using finite difference method. The research is of great significance to the construction and reinforcement of expansive soil slopes in South-to-North Water Diversion Project.

Abstract: Through the model test in soil slot,the process of deformation and destruction of soft pipeline caused by subsoil settlement is simulated and observed in lab. Based on the experimental data, the curve as the internal force of pipeline is first drawn out and discussed, in turn the characteristic of stress distribution and destruction rule of pipeline are analyzed and summarized, which may be referred for designer to take appropriate measures. The experimental results show that the internal force and deflection of the pipeline increase with the depth and width of the hole below the pipeline. When the hole depth (h)/ pipeline diameter (D) =2.5, internal force and deflection changes only associate with the width of the hole (b). And when b/D =6, the pipeline can not work normally and even be destroyed. The experimental conclusion can provide the basis for the security of underground pipeline.

Abstract: The subject of Foundation Excavation near the buried pipeline line. Compared with each other using a scale model of the buried pipeline foundation excavation factor of the vertical displacement, and connected with the buried pipeline displacement of both ends of the fixed elastic beam theory; analysis of the factors affecting the displacement of buried pipelines, the good agreement of the theoretical results with the scale model test value.

Abstract: To study the deformation of soil when interacting with structure, this paper macroscopically analyzes sand deformation field through the direct shear test with sand and steel plate. The test used the invisible semi-model shear device to take photo of experimental process for analysis by digital photography-based deformation measurement(DPDM) technique. The results show that during the process of interaction between dense sand and structure, the influence made by normal stress is more significant than that of compactness. As the normal stress grows, the compactness, the maximum shear stress and the bulk strain of medium sand correspondingly increases. At the beginning of shear, sand far from the plate displays shear shrink while sand close to the plate shows partial shear dilatancy.

Abstract: In this paper, through the design of the technical parameters, construction quality control points, the matters needs to be pay attention of cement mixing pile in soft ground treatment to analye the working properties in a flexible foundation of cement mixing pile and discuss the design methods of flexible foundation of cement mixing pile.

Abstract: GEO-groove simulation experiment is applied to imitate the Taiyuan soil subsidence in pipeline base and side by soil loss, which eventually leads the pipeline to be deformed and destroyed. The pre-damage standard is set up though analyzing test statistics and drawing it’s sedimentation and damage curve. The damage standard of sewage line is achieved through setting up a very pilot model to the test and analyzing it’s bearing force characteristics, and according to the gotten sedimentation curve of the test, damage characteristics and mechanism of sewage line is analyzed , thus will give the designing and application of pipeline of testing and theory basement, so as to take measures to protect pipeline in practical situations, establish early warning system to pipeline, and guarantee it’s regular service.

Abstract: Random mining by small coal mines left many destruction districts with a large range in Fenxi mining district. According to incomplete statistics, the destroyed areas by small coal mines amount to nearly one hundred square kilometers and have over three hundred million tons of resource reserves in Xinliu, Xinyu and Xinyang these three fields. Small coal mines tend to use outdated techniques such as replacing mining with advancement, small excavation with large stoping and room pillar mining technique, which have a stoping rate of only 10% to 25%. Some of the wellheads were not closed seamlessly, which resulted in self-combustion; some were damaged due to the mining of the lower coal seam. A serious security risk existed during the mining of the lower coal seam due to the uncertainty of gas, water and roof pressure. In addition, the destructed area by small coal mines is badly large in Shanxi Province and even the whole country which remains a huge amount of resources. The implementation of this subject is significant.