摘要
为考虑基坑宽度对基坑抗隆起稳定性影响,以临界值L_(0)(L_(0)=√2DD_(1)-D^(2)其中,D为围护体插入深度,D_(1)为最下道支撑点到围护体端点的距离)为标准对基坑宽度L进行分类,当L≤L_(0)时为窄基坑,当L>L_(0)时为宽基坑。对于窄基坑,本文提出其隆起滑动面是以最下道支撑点为轴心呈抛物线型态的假定,并推导出窄基坑抗隆起稳定性安全系数计算解析解,应用该式计算所得的抗隆起稳定性安全系数均小于现有改进计算方法的计算结果,与离心物理模拟试验结果更相符,满足潘家铮先生提出的滑坡极小原理。本文提出的抛物线滑动模式与现行规范计算方法有很好的相融性,滑弧仍以基坑最下道支撑点为轴心,滑弧形状也可以从窄基坑时的抛物线型过渡到宽基坑的圆弧型,计算假定条件也相同,为今后修订规范提供了一条可选择的途径。
In order to consider the influence of excavation width on the stability of foundation pit against uplift failure,the excavation width is classified according to the critical value L_(0)(L_(0)=√2DD_(1)-D^(2),D is the depth of penetration and D_(1)is the distance from the lowest supporting point to the end point of retaining body).When L≤L_(0),it’s a narrow foundation pit.If L>L_(0),it’s a wide foundation pit.For narrow excavation,the assumption that uplift sliding parabolic surface with the lowest supporting point as the axis is proposed in this paper.The analytical solution for calculating the safety factor of anti-uplift stability of narrow excavation is deduced.The value of safety factor of anti-uplift stability calculated by this formula is less than the calculation result of the existing improved calculation method,which is more consistent with the centrifugal physical simulation test results.It meets the landslide minimization principle proposed by Mr.Pan Jiazheng.The parabola sliding mode proposed in this paper has a good compatibility with the calculation method of the current specification.The sliding arc still centers on the lowest supporting point of the foundation pit.And because the calculation assumption is same,the shape of the sliding arc can also changes from parabola in narrow excavation to circular arc in wide excavation,which provides an alternative way for revising the specification in the future.
作者
阳吉宝
黄星
YANG Jibao;HUANG Xing(Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092,China)
出处
《建筑结构》
CSCD
北大核心
2021年第S02期1495-1503,共9页
Building Structure
关键词
基坑宽度
窄基坑
隆起破坏
插入深度
抛物线滑动型态
excavation width
narrow excavation
uplift failure
depth of penetration
parabolic sliding form
作者简介
阳吉宝,博士,教授级高级工程师,Email:yangjibao@smedi.com。
