【摘要】 应用LS-DYNA3D软件对某地下工程改扩建中施工爆破作业进行了三维数值模拟,分析了围岩与衬砌中爆炸应力波的传播特征,指出了原有洞室混凝土衬砌的破坏主要为施工爆破诱发的反射拉伸波使衬砌拉应力超过混凝土抗拉强度所导致拉裂破坏,且破损现象主要发生在洞室的侧墙部位,为控制衬砌破损的进一步发展,建议采用台阶法开挖,计算表明台阶法开挖能明显改善衬砌拉应力水平和质点振速。更多还原

【Abstract】 Drilling-blasting excavation for underground cavern enlarging is simulated and analyzed by using the LS-DYNA 3D software.The characteristics of the propagation of stress wave in rock stratum and lining under explosive loading are analyzed.The results of numerical simulating indicate that reflecting tensile wave directly results in concrete lining fracture owing to tensile stress over the tensile strength of concrete and the damage usually locates in lining wall.It is also demonstrated that steps excavation method is better than full section excavatio because of decreasing the lining tensile stress and particle vibration velocity.更多还原