基坑工程中长短桩支护形式数值模拟研究

STUDY ON NUMERICAL SIMULATION OF LONG-SHORT PILE SUPPORT IN FOUNDATION PIT ENGINEERING

武汉地区广泛分布有深厚软土,采用长短支护桩进行基坑支护具有良好的经济性、适用性,但对于其支护原理的研究却甚少。文中结合具体的基坑工程实例,运用有限元软件MidasNX对长短桩支护形式进行数值分析并与实际监测数据对比。结果表明长短支护桩水平位移在正常范围内,基坑处于安全稳定状态;模拟过程中短桩存在‘踢脚’现象,而长桩变形在桩底逐渐收敛;数值计算得到的长桩与短桩最大弯矩值一致,这与设计软件计算值存在差异。

Deep soft soil is widely distributed in Wuhan area. It has good economic and applicability when using long and short supporting piles for foundation pit support, but little research has been done on its supporting principle. In this paper, combined with the concrete foundation pit engineering example, the finite element software Midas NX is used to numerically analyze the supporting forms of long and short piles and to compare with the actual monitoring data. The results show that the horizontal displacement of long and short supporting piles is within the normal range, and the foundation pit is in a safe and stable state;In the process of simulation, the phenomenon of “kicking” exists in short piles, while the deformation of long piles converges gradually at the bottom of piles;The maximum bending moment value of long and short piles calculated by numerical method is identical, which is different from that calculated by design software.