黄土地区水平荷载作用下闭合型地下连续墙基础承载 性状分析

地下连续墙基础相对于一般桩基础的一个显著特点就是整体刚度大,水平荷载作用下基础一般有两种工作状态和破坏机理:其一是刚性短桩,表现为转动或平移破坏;其二是弹性长桩,表现为挠曲破坏。数值模拟表明:在一定范围内随着墙体埋深的增加,在大小相等的水平荷载作用下,基础埋深越大,其水平位移则越小。但埋深超过30m后,墙体埋深对基础的水平变形影响变得不显著。即当闭合墙体的埋深超过一定深度后,过分的加大闭合墙体的埋深无助于提高基础的水平承载性能。

HORIZONTAL LOAD-CARRYING CAPABILITY OF CLOSED DIAPHRAGM WALL IN LOESS AREA

According to pile foundation, a closed diaphragm wall has a relatively large stiffness. Because of the great stiffness difference between ferroconcrete and soil, under horizontal load, two types of failure form. Their mechanism can be found via numerical emulation and in-situ test. One is rotary failure, which is associated with rigid short piles. The other is flexible failure, which is associated with elastic long piles. Inside certain buried depth of a diaphragm wall, the buried depth of diaphragm wall notably affects the horizontal load-carrying capability of closed diaphragm wall foundation. Under the same geological condition, when the buried depth of diaphragm wall exceeds 30 m, the buried depth does not notably control the horizontal load-carrying capability of the foundation.