基坑土钉支护的突变分析

Catastrophe analysis of soil nailing support in foundation pit

尝试着将系统科学中的突变理论引入到土钉支护的理论分析当中来,从传统的研究事物连续、光滑、不间断的变化转入到研究事物不连续变化的工作中来.研究中使用了突变理论中最常见的折叠型突变和尖点突变,分别对土钉支护体系中的土体和土钉与土体之间的粘结摩擦力进行分析,以势函数为响应变量,以基坑侧向位移为主要的控制变量,求解出了基坑发生突变时的临界位移,并通过临界位移,对开挖中的基坑进行安全性的评价.通过具体工程的分析,计算出了土钉支护体系发生突变的两种主要破坏方式的临界位移,对比两种临界位移,判断土钉支护体系的破坏形式.

In the present work, the catastrophe theory based on the system science is introduced for the theory analysis on the soil nailing support. The non-confinuing alteration was studied instead of continual, smooth alteration. The common fold catastrophe and cusp catastrophe was employed for analysising the soil in the soil nailing support system and the friction between soil and soil nailing. Furthermore, the power function and the vertical displacement of foundation pit are applied as the response variable and control variable respectively to solving the critical displacement when the catastrophe occurs in the foundation pit. Through this the safety evaluation is executed afterwards. Eventually, by the use of a real example, two critical displacements wereealeulated when the soil catastrophe occurred or the friction catastrophe occurred. The soil nailing support system＇s broken style through those two critical displacements are dctermined.