The influence of stiffness coefficient of steel support on supporting effect and its optimization

Abstract

The stiffness coefficient of steel support plays an important role in controlling the deformation of foundation pit, but the influence of various parameters in the stiffness coefficient on the supporting effect of foundation pit is still unclear, resulting in the unreasonable value of the stiffness coefficient. By means of theoretical analysis and numerical simulation, this paper makes a comprehensive and in-depth study on the influence law and optimization of the stiffness coefficient of steel support on the supporting effect. Based on the calculation of the stiffness of steel support, the calculation formula of the stiffness of steel support under the uniform radial load is derived by using the basic definition of stiffness calculation; the change rules of horizontal displacement and surface subsidence of the support structure under different parameters were analyzed by numerical simulation method, and the original scheme was optimized. The results show that: (1) in the stiffness coefficient, the steel support spacing and wall thickness have a great influence on the supporting effect; (2) with the increase of the rigid support spacing and the decrease of the steel support wall thickness, the horizontal displacement value and surface settlement value of the support structure both become larger. However, when the steel support spacing is 3.00-3.10m and the steel support wall thickness is 14mm-16mm, the horizontal displacement value and surface settlement value of the support structure do not change much, and they are all within the monitoring and warning value; (3) the original design scheme was optimized from 3.00m steel support spacing and 16mm steel support wall thickness to 3.10m steel support spacing and 14mm steel support wall thickness in the original scheme, which reduced the engineering cost and improved the construction efficiency.