抗浮锚杆及锚杆抗浮体系稳定性验算公式研究

抗浮锚杆及锚杆抗浮体系的抗浮稳定性验算公式宜采用综合安全系数法、分项系数表达方式。群锚稳定性验算可简化为单锚稳定性验算,验算模型可按上半部分长方体、下半部分圆锥体的假定破裂面形状,锥尖深度为锚固段计算长度与自由段长度之和。群锚整体抗浮承载力为单锚抗浮承载力之和,单锚抗浮力设计值可取假定破裂体内岩土体重量与破裂面黏聚力提供的摩阻力分别除以分项安全系数后之和,分项安全系数取值水准为1.5及3.0。锚杆抗浮体系稳定性验算公式中,抗力设计值可取建筑物自重标准值及其上作用的永久荷载标准值之和除以1.05的安全系数、抗拔桩的抗浮承载力设计值、抗浮锚杆的抗浮承载力设计值三者之和,而浮力设计值则取建构筑物基底静水压力标准值。

Formulae for calculating stability of anti-floating anchor and anchor anti-floating system

The comprehensive safety factor methods and partial safety factor expressions should be adopted for the formulae to calculate the stability of anti-floating anchor and anchor anti-floating system. The model for the stability of anchor groups can be simplified as that of single anchor, the fracture surface is assumed that the upper part is cuboid and the lower part is cone, and the depth of conical tip is the sum of the fixed anchor length for calculation and free anchor length. The whole anti-floating bearing capacity of the anchor group is the sum of that of the single anchor. The anti-floating bearing capacity of the single anchor is the sum of the weight of soils inside the fracture body and the frictional resistance supplied by cohesive force on the assumed fracture surface divided by the partial safety factor, which is 1.5 and 3.0, respectively. In the formula for calculating the stability of anchor anti-floating system, the design resistance value is the sum of the design of values anti-floating bearing capacity of uplift piles and anti-floating anchor and the standard weights of buildings and permanent loads on them divided by safety factor of 1.05, and the design value of buoyancy is the hydrostatic pressure at the foundation bottom of buildings.