落石冲击下钢筋混凝土桩板墙的动态响应

Dynamic damage model for reinforced concrete pile-plate retaining wall under rockfall impact

为了研究钢筋混凝土桩板墙在落石冲击下的动态响应全过程,特别是其损伤特性,首先,将冲击损伤对材料弹性模量的影响引入到经典的Hertz接触理论中;其次,借鉴基于冲量定理的最大落石冲击力计算公式,提出新的最大落石冲击力计算公式;最后,根据钢筋混凝土桩板墙在落石冲击下的动态力学响应过程,提出落石冲击下钢筋混凝土桩板墙的动态损伤模型,并利用该模型对落石冲击力进行参数敏感性分析。研究结果表明:该模型能较好地反映落石冲击下钢筋混凝土桩板墙的3个变形阶段,即:弹性加载阶段、塑性损伤加载阶段和弹性卸载阶段;冲击速度和落石半径对钢筋混凝土桩板墙的动态力学响应影响较大,而钢筋混凝土桩板墙的损伤参数δ_(c)和γ对计算结果影响较小,但是当γ较小时,其影响较显著。

In order to study the whole dynamic response process of the reinforced concrete pile-plate wall under rockfall impact,especially its damage characteristics,firstly,the effect of impact damage on material elastic modulus was introduced to the classical Hertz contact theory.Secondly,in view of the formula of the maximum rockfall impact force based on the theorem of impulse,a new formula of the maximum rockfall impact force was proposed.Finally,according to the dynamic mechanical response process of the reinforced concrete pile-plate wall under rockfall impact,a dynamic damage model for the reinforced concrete pile-plate wall under rockfall impact was proposed.The model was used to analyze the parameter sensitivity of rockfall impact force.The results show that the proposed model can reflect the following three deformation stages of the reinforced concrete pile-plate wall under rockfall impact,e.g.,elastic compression stage,plastic damage compression stage and elastic resilience stages.Impact velocity and radius of rockfall have great effects on the dynamic response of the reinforced concrete pile-plate wall,while the effect of damage parameters δ_(c) and γ on the calculation is less.Whenγis small,its effect is rather larger.