条形荷载下黏性土主动土压力计算

Calculation of active earth pressure for cohesive soil under action of strip surcharge

依据库仑土压力理论假设,挡土墙土压力由墙后填土在极限平衡状态下出现滑动楔体产生,推导出考虑滑裂面上填土的黏聚力、墙土间黏聚力、黏性土表面出现张拉裂缝、条形荷载下的黏性土主动土压力计算式,并给出临界破裂角的显式解答。当墙后作用有连续均布荷载或不考虑黏性填土表面出现裂缝时,只需取条形荷载到墙顶的距离或计算的裂缝深度为0即可按相同的方法求解。研究表明,由于未考虑条形荷载对临界破裂角的影响,规范方法得到土压力值偏小。该公式适用范围广,尤其对于条形荷载作用墙后任意位置时均可应用,对实际工程中挡土墙的设计计算具有一定应用价值。

Based on the Coulomb's earth pressure theory hypothesis that active earth pressure against the back of retaining wall is due to thrust force exerted by a sliding wedge of soil between the back of the wall and a plane which passes through the bottom edge of the wall and has an inclination of θ,a formula of active earth pressure is proposed,which considers the cohesion force on the sliding plane,the adhesive force between soil and the retaining wall,tension crack appears on the surface of cohesive soil,the strip surcharge;and the explicit solutions of critical rupture angle are given.When continuous uniform load acts on the back of the wall or without considering the situation that tension crack appears on the surface of cohesive soil,it can be solved by the same method with zeroing the distance from the strip surcharge to the coping and that the calculation of crack depth.Studies have shown that the calculation result of earth pressure based on specification is small,as the influence of strip surcharge on critical angle of rupture doesn't count.The formula has a wide range of application,especially for the case that the strip surcharge acts on arbitrary position behind the wall.It has a certain practical value for the design and calculation of retaining wall in practical projects.