基坑内预留土堤对基坑性状的影响分析  

Effect of berms on behaviors of excavation supported by sheet-pile walls

作　　者：陈福全[1] 吴国荣[2] 刘毓氚[1] 

机构地区：[1]福州大学土木工程学院,福建福州350002 [2]浙江海洋学院船舶系,浙江舟山316004

出　　处：《岩土工程学报》2006年第B11期1470-1474,共5页Chinese Journal of Geotechnical Engineering

摘　　要：对粘性土基坑中预留土堤作用下的悬臂式排桩支护基坑性状进行不排水数值分析,研究了土堤尺寸、桩土相对刚度等各种因素影响。分析表明:在临时支挡结构前预留土堤可以明显地减小支挡结构变形和支护桩的嵌入深度与弯矩,从而降低工程造价。只要土堤自身稳定性满足要求,合理地增大土堤宽度和高度,可以减小基坑的变形和桩身弯矩,但在较小的坡度条件下无论是在粘土层中还是砂性土层中,预留土堤高度低于1.5 m,宽度小于2.0 m时比较经济。支护桩的刚度越大,要更大的土堤宽度才能有效地减小支护结构的侧移;粘土层不排水强度越大,土堤尺寸对侧移的影响就越小。A series of finite element analyses were carried out to investigate the effect of earth berms located in front of temporary sheet-pile walls on the behaviour of excavation. For the particular wall and pit geometry and soil layer conditions considered in these analyses, relationships between the wall lateral displacement, the width and height of berms, sheet-pile stiffness and the undrained strength of clay were presented and discussed. The results show that berms can prevent excessive wall displacement and minimize excavation costs. So as the berm is steady, it is more economical when the width of berm is lower than 2.0 m, and the height is lower 1.5 m. The stiffer the sheep-pile walls, or the lower the soil stiffness, the greater the berm width required to reduce piles lateral displacements and bending moments.

关 键 词：数值分析 基坑 预留土堤 排桩支护结构 

分 类 号：TU472[建筑科学—结构工程]