基于时程法的重力坝动力抗滑稳定研究

Dynamic Anti-Sliding Stability of Gravity Dam Based on Time-History Method

以重力坝整体失稳破坏为评判准则,研究地震荷载作用下重力坝的抗滑稳定性,根据塑性区分布情况、计算收敛性以及瞬时安全系数可综合判断大坝的安全度。从分析结果来看:无论是沿建基面的抗滑稳定,还是坝基软弱结构面的深层抗滑稳定,随着地震加速度的增大,塑性区都逐渐增大,并最终出现贯穿性塑性区;沿滑动面的安全系数随地震加速度时程的变化而变化,最小安全系数分布与塑性区的发展情况类似,因此可对塑性区分布和瞬时安全系数进行综合评价后再对坝体抗滑稳定性进行判断。

The anti-sliding stability of gravity dam under seismic load was studied based on the rule of dam sliding stability and the safety ofgravity dam was determined according to the plastic zone,computational convergence and transient safety factor. The results show that alongwith the enlargement of the seismic acceleration,the plastic zone located on dam foundation surface and weak structural plane appeardiscontinuously and finally a discontinuous plastic zone appears,while,the minimum safety factor also appears. Based on the above factors,the stability of gravity dam can be determined.