动荷载作用下基坑支护结构动力响应研究

应用Midas/GTS数值分析软件对车辆动荷载作用下基坑支护体系的动力响应进行了模拟分析。通过调整车速和车辆行驶位置系统地分析了不同车速行驶动荷载作用下基坑支护结构的内力及位移变化情况。研究发现,基坑桩锚支护体系中锚杆轴力随车速提升呈先增大后减小的规律,支护桩整体结构在车速动荷载影响下与锚杆轴力呈相同变化趋势,汽车在一定行驶速度范围内,随着车速的提升支护桩位移逐渐增大,达到波动峰值后位移变小;车辆距离基坑边线的行驶位置与桩锚支护结构受力变化呈非线性关系,距离越近影响变化越明显。结合具体工程实例,通过对现场监测数据分析并与数值模拟结果进行对比,结果表明,数值模拟与现场监测得到的基坑支护体系内力及位移变化规律一致,数值模拟技术工程指导效果显著。

Study on dynamic response of the foundation pit supporting structure under dynamic load

The dynamic response of foundation pit supporting system under vehicle dynamic load was simulated and analyzed by using Midas/GTS numerical analysis software.By adjusting the vehicle speed and vehicle driving position,the changes of internal force and displacement of foundation pit supporting structure under different speed dynamic load were analyzed systematically.The results showed that the axial force of anchor in the pile-anchor supporting system of foundation pit increased at first and then decreased with the increase of vehicle speed,and the whole structure of supporting pile changes in the same trend as the axial force of anchor under the influence of vehicle speed and dynamic load.Within a certain range of driving speed,the displacement of the supporting pile increased gradually with the increase of the vehicle speed,and became smaller after reaching the fluctuating peak value.There is a nonlinear relationship between vehicle driving position and stress change of the pile-anchor supporting structure.The closer the distance was,the more obvious the change was.Combined with a specific engineering example,through the analysis of the on-site monitoring data,compared with the numerical simulation results,the results showed that the internal force and displacement of the foundation pit supporting system obtained by numerical simulation and on-site monitoring were consistent.The engineering guidance effect of numerical simulation technology was remarkable.