Analysis of Deformation Failure and Supporting Structure Force Evolution of Deep Foundation Pit Under Compound Supporting(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2015年03期
- Page:
- 74-80
- Research Field:
- Publishing date:
Info
- Title:
- Analysis of Deformation Failure and Supporting Structure Force Evolution of Deep Foundation Pit Under Compound Supporting
- Author(s):
- HUANG Zhi-quan; LI Xiao-hui; SUN Yi; LI Lei
- School of Resources and Environment, North China University of Water Resources and Electric Power
- Keywords:
- compound supporting; deep foundation pit; deformation failure characteristic; supporting structure; plastic zone; threedimensional numerical analysis
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to simulate the actual working conditions of excavation and supporting in a deep foundation pit project, a threedimensional numerical model was built using geotechnical numerical analysis software FLAC 3D, and the deformation failure and supporting structure force evolution characteristics of the deep foundation pit under double micropiles and composite soil nailing were analyzed. The results show that horizontal displacement contours of the foundation pit wall is bulging, indicating a small displacement in the upper but a big displacement in the lower. A larger uplift appears at the bottom of the foundation pit, but the uplift amount decreases with the decreasing of distance from foundation pit wall. Besides, vertical settlement of the foundation slope is small, and the maximum settlement appears after the supporting structure. The axial force of soil nail is strong in the middle and weak at the end, and the maximum axial force point is getting closer to the excavation face when approaching to the bottom of the foundation pit. With the increase of the excavation depth, the axial forces of soil nail grow quickly at the beginning and then become slow. The bending moment of the front micropiles is greater than the back row, and the maximum bending moment appears at 2 meters depth of the bottom of the foundation pit after the excavation completed. Moreover, the stability of foundation pit is obtained by the support of measuring points displacementtime curve and the plastic zone distribution characteristic. However, tensiontensile plastic zone appears in the top of the hill edge, and the shear failure zone appears in the shallow of foundation pit wall and bottom of foundation pit, respectively, indicating the proper protecting measures should be taken. The obtained results can provide significant reference for the dynamic evolution and prevention of deformation failure in deep foundation pit excavation.
Last Update: 2015-05-27