1 / 7 悬臂式板桩和板桩稳定性计算计算书一、编制依据本计算书的编制参照《建筑基坑支护技术规程》(JGJ120-99),《土力学与地基基础》(清华大学出版社出版)等编制。二、参数信息重要性系数: 1.00;开挖深度度 h:2.55m;基坑外侧水位深度 hwa:3.4m;基坑内侧水位深度 hwp:0.80m;桩嵌入土深度 hd:4m;基坑边缘外荷载形式:无荷载悬臂板桩材料: 20号槽钢;弹性模量 E:206000N/mm2;强度设计值 [fm] :205N/mm2;桩间距 bs:0.10m;截面抵抗矩 Wx:191.4cm3;截面惯性矩 Ix:1913.70cm4;基坑土层参数:序号 土名称土厚度坑壁土的重度内摩擦角内聚力 浮容重(m) (kN/m3) ( °) (kPa) (kN/m3) 1 粘性土4.3 18.2 7.5 12.2 18.2 2 粘性土2.1 18.3 5.6 11.8 18.3 3 粉土2.2 18.6 17.3 11.3 18.6 4 粘性土5.3 19.3 6.5 37 19.3 三、土压力计算2 / 7 1、水平荷载(1)、主动土压力系数:Ka1=tan2(45°- φ1/2)= tan2(45-7.5/2)=0.769;Ka2=tan2(45°- φ2/2)= tan2(45-7.5/2)=0.769;Ka3=tan2(45°- φ3/2)= tan2(45-5.6/2)=0.822;Ka4=tan2(45°- φ4/2)= tan2(45-17.3/2)=0.542;(2)、土压力、地下水以及地面附加荷载产生的水平荷载:第1层土: 0 ~ 3.4米;σa1上 = P1K a1-2C1K a10.5 = 0 ×0.769-2 ×12.2 ×0.7690.5 = -21.398kN/m;σa1下 = ( γ1h1+P1)Ka1-2C1K a10.5 = [18.2×3.4+0] ×0.769-2 ×12.2 ×0.7690.5 = 26.193kN/m;第2层土: 3.4 ~ 4.3米;H2' = ∑γihi/ γ2 = 61.88/18.2 = 3.4;σa2上 = [ γ2H2'+P1+P2a2/(a2+2l2)]K a2-2C2Ka20.5 = [18.2 ×3.4+0+0] ×0.769-2 ×12.2 ×0.7690.5 = 26.193kN/m2;σa2下 = [γ2H2'+P1+P2a2/(a2+2l2)]K a2-2C2Ka20.5+γ'h2K a2+0.5γwh22 = [18.2 ×3.4+0+0] ×0.769-2 ×12.2 ×0.7690.5+18.2 ×0.9 ×0.769+0.5 ×10×0.92 = 42.841kN/m2;3 / 7 第3层土: 4.3 ~ 6.4米;H3' = H2' = 3.4;σa3上 = [γ3H3'+P1+P2a2/(a2+2l2)]K a3-2C3Ka30.5+γ'h3K a3+0.5γwh32 = [18.3 ×3.4+0+0] ×0.822-2 ×11.8 ×0.8220.5+18.3 ×0.9 ×0.822+0.5 ×10×0.92 = 47.349kN/m2;σa3下 = [γ3H3'+P1+P2a2/(a2+2l2)]K a3-2C3Ka30.5+γ'h3K a3+0.5γwh32 = [18.3 ×3.4+0+0] ×0.822-2 ×11.8 ×0.8220.5+18.3 ...