深基坑坑壁土压力模式与支护结构安全分析

润扬长江公路大桥北锚碇深基坑工程采用地下连续墙作为围护结构.施工过程土压力沿坑深变化有直线递增、波状递增、附加荷载作用等分布模式.对不同土压力分布模式下支护结构内力进行分析得出:直线递增(三角形)荷载作用下,整个墙身上部弯矩较小,下部则较大;波状递增土压力形式作用下,整个墙体挠曲多变,并且在中上部就有较突出的弯矩作用;附加荷载土压力模式作用下,墙身上部弯矩异常突出.该分析结果对支护结构的可靠性设计具有重要意义.

Different models of the earth pressure on the deep foundation pit wall and the safty of retaining structure

Diaphragm wall was designed as the enclosure system for the north anchor deep foundation pit of the Runyang bridge.By analyzing the monitoring data of the earth pressure on the wall,three earth pressure models were sum up,that is,the straight line increase,undulance increase and extra load pattern etc.The internal force of the retaining structure under different earth pressure models was analyzed in this paper.Under the straight line model of earth pressure,the moment of the wall was small in upside and big down below;under the undulance model,the wall was bend changefully and the moment was distinct in the middle-upside of the wall;under the extra load pattern of earth pressure,the moment was obviously big in the upside of the wall.All these calculation results will be very important to reliability design of retaining structure.