护坡桩与窄槽土压力计算

高层建筑常设地下室(一层或多层)以作车库、设备层及人防等用途.而作用于地下结构物(如上述地下室)周边侧墙上的土压力分析,根据边坡稳定所采取的方法不同而有所区别:当基坑周边采取放坡大开挖时,由于结构物外墙与坡面之间形成“宽槽”,回填土对侧墙压力分布可近似按朗肯(Rankin)主动土压力计算;当采用排桩等支护时,由于外墙与排桩墙之间仅留约1m的施工通道,形成“窄槽”,回填后呈窄槽填土带,因此作用在侧墙上的土压力,应属“窄槽土压力”计算法.目前,对后一方法的设计,屡因概念失准,配筋超常,浪费较大.本文以散体极限平衡法导出窄槽土压力计算公式,最后以简洁的表达式与一组“K_g～z/B曲线”提供设计直接查用,也为“高规”基础设计作一补白.此外,文中还对基础埋深、沟槽性状、护桩功用等给予阐述,并对地下室抗震设计提出了新的观点.

Calculation of the Earth Pressure for the Narrow Trough and the Slope Protection pile

In accordance with bulk soilds ultimate equilibrium method, the computational formula for earth pressure of the narrow trough is developed. The simple formula and a group of Kg-z/B carves put forward can be using in design directly. The foundation embedment, states of trench, fouction of slope protection piles and new aseismic design viewpoints on basement were also presented.