Study on the Slope Deformation Failure Mechanism, the Support Design and the New Construction Technology of Foundation Pit with Red Clay
|Keywords||Deep foundation pit of red clay On hard under soft Support design Stability analysis Numerical simulation Guiyang The pressure of anchoring decentralized Advance support|
With the rapid development of the western region in China, the scale of capital construction is expanding promptly and the construction of high and ultra-high-rise building enter rapid development stage. For the increase of foundation pit excavation and support, the excavation stability has been more and more concerned by scientist and engineer. Therefore this paper applies the method of theoretical calculation and numerical simulation to analyze the stability of excavation which is Guizhou kaiyang Phosphate office. Achievements are made in the following five aspects:1. Based on the research of formation、material composition、structural characteristics、physical and mechanical properties of guizhou red clay and the engineering problem of red clay foundation , find out that the guizhou red clay has the engineering characters such as high moisture content、high plasticity large void ratio low permeability high load high-shrinkage and large difference between shear performance. Therefore the different between other types of clay is that guizhou red clay has poor indicators of the physical properties and good mechanical properties.2. Based on the characteristics of foundation pit excavation, this paper researches the deformation and failure mechanism and emphasis on the commonly used applications of excavation support and their condition.3. For instance of the excavation of kayang phosphate office, this paper applies the theoretical analysis to stability of excavation and then designs the form of support, such as anchor (cable) wall. The calculation result is that the excavation is entire stable after the support.4. By the use of numerical simulation to analyze deformation and failure characteristic of the excavation and compared to the actual work, the result shows that the method which analyzed the stability of deep foundation by FLAC3D software is feasible. So the method of numerical simulation could be used in the construction process simulation to predict the development of deformation change and identify the weak areas to guide the construction to take further effective measure.5. Compared with other traditional anchor methods, the pressure of anchoring decentralized system will be concentrated load for a few scattered smaller loads in different parts of the fixed section. So that the peak bond stress greatly reduced due to the fixed cable unit and the length is very small. The bounding effect would not be gradual weakening. According to the experiment in kayang, the result is that the dispersion in the pressure-type anchorage system in the red clay of deep excavation on the role of the superior to the traditional way of support.