Papers by Author: Qing Hui Jiang

Abstract: The deep foundation pit engineering of Wanda Plaza in Yinchuan city is taken as a case study and the corresponding numerical model has been built. The deformation and stability of the foundation pit during sequential excavation has been analyzed by using of the FLAC3D software. The weak positions which may lose the stability are predicted by the results from the numerical simulation. A soil-nailing reinforcing scheme has been proposed to maintain the stability of the foundation pit. To analyze the support effects of the soil-nailing, the Cable structure elements have been adopted to simulate the interaction between soil and soil-nailing. The calculation results show that the maximum horizontal displacement occurs in the middle part of the pit wall and the minimum occurs in corner part of the pit wall. The soil nailing support significantly decreases the deformation of foundation pit by dispersing internal stress of soil. The reliability of the simulation results has been verified by the comparative analysis between the numerical simulation results and the deformation monitoring data of foundation pit. The proposed reinforcement scheme is not only helpful to ensure the safety of Wanda Plaza foundation pit，but also provides valuable experiences for the reinforcement of similar foundation pit engineering.

Abstract: With RMT-150C rock testing machine and AEWIN E1.86 DISP acoustic emission system applied, the acoustic emission test was accomplished with two kinds of rock samples including marble and granite under uniaxial compression. Cyclic loading and continuous loading were used through the experiment, and the mechanical performance and acoustic emission (AE) characteristics were obtained during the process of rock progressive failure. Details related to the relationship between amount of AE and stress-strain was given in this paper. A comparison between marble and granite was made as well following the general AE law, on the basis of which, the failure mechanism of rock mass was investigated. Finally, some conclusions can be summarized as follows:(1) AE activity features are different with stress state variation in rock failure process;(2) loading patterns make a direct impact on the failure process thereby affecting AE activities;(3)AE activities are various basing on the different types of rocks, structures and failure modes.

Abstract: Wanjiakouzi arch dam is constructed in a complex geological site, where a large number of faults, interlayer shear bands and karst zones exist in the dam foundation and abutments. The weak rocks have a bad effect on the stability of the arch dam. In this paper, the displacement distribution and stress field of the arch dam are analyzed using 3D nonlinear finite element method. The numerical results show that displacement between both left and right bank abutments is obviously asymmetric and there is greater compression and shear deformation along the faults under the thrust of the arch dam. Furthermore, the tensile stress at dam heel cannot meet the requirement of the design specifications. Therefore, it is necessary to reinforce the dam foundation and abutments to improve the ability to resist deformation of abutment. By taking such reinforcement measures as concrete plugs and consolidation grouting for weak zones, the asymmetric displacements between abutments are decreased significantly and the tensile stresses of dam heel meet the stability requirement.