土钉墙支护结构破裂角的研究.pdf

2011年4月上 施工技术 第40卷第338期 CONSTRUCTION TECHNOLOGY 41 土钉墙支护结构破裂角的研究 袁洪升 (廊坊师范学院建工学院，河北廊坊065000) [摘要]土钉支护技术已广泛应用于一般的基坑和边坡工程中，规范中对土钉支护结构进行设计时，采取破裂面为 直线，破裂角取45°/2.借助准黏聚力理论，认为土体中设置土钉后，土体的内摩擦角不变而粘聚力变大，土体 的抗剪强度增强.而且在土体中设置土钉后，改变了土体的应力状态，主应力方向发生偏转，土体的滑裂面相应改 变.通过对土钉支护结构中的土体单元进行应力分析，得出了垂直基坑中土钉支护结构滑移面的破裂角为45° 单2-.结果表明土钉剪切滑移面破裂角与土体内摩擦角和七钉倾角有关，均成线性关系. [关键词]土钉墙；准黏聚力；应力莫尔圆；滑移面：破裂角 [中图分类号]TU413.62 [文献标识码]A [文章编号]1002-8498(2011)07-0041-03 Research on Rupture Angle of Soil-nailing Wall Structure Yuan Hongsheng Institute of Civil Engineering and Architecture Langfang Teachers College Langfang.Hebei 065000 China) Abstract:Soil-nailing support technology is applied in general foundation excavation and slope widely. The rupture plane of soil-nailing structure is thought as a straight line and the rupture angle is45°p/2 in standard.Based on theory of pseudo-cohesion the angle of internal friction of soil is invariant while the cohesion is getting bigger and shear strength of soil is getting strengthened after the soil-nailing is fixed in the soil.When the soil-nailing is fixed in the soil the stress state of soil is changed the principal stress direction deflects and the rupture plan changes in response.The formula of ruptured angle 45°/2-in the soil-nailing structure of vertical foundation excavation is derived through the stress analysis of soil unit in the soil-nailing structure.It is indicated that the rupture angle of shear-sliding plane in the soil-nailing structure is linearly related to th...