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.