冲击荷载下浅埋框架结构上的动载计算分析

Dynamic Load Analysis on Shallow Buried Frame Structure under Impact Load

城市化建设不断加快,爆破拆除引起的建(构)筑物塌落冲击效应,对浅层地下结构安全影响已成为关系到城市可持续发展的重大问题。基于强夯动应力理论,提出了建筑物塌落冲击自由场动应力计算模型,并与试验结果进行对比验证,表明模型计算结果最大误差在8%左右,而且能较好地表示动应力随深度的衰减规律。基于该模型并考虑土与结构的相互作用,推导了地表冲击下浅埋框架结构上动载的计算公式,并分析了结构柔度对刚性地基上浅埋结构动载的影响。分析结果表明,适当增加地下结构的柔度可降低结构所受到的动力荷载。

With the acceleration of urbanization,the impact of blasting demolition on the safety of shallow underground structures has become a major problem related to the sustainable development of cities.Based on the theory of strong ramming dynamic stress,a free field dynamic stress calculation model for collapse impact of buildings is put forward,which is verified by comparison with the test results,which shows that the maximum error of the model is about 8%,and the attenuation law of dynamic stress with depth can be expressed well.Then,based on the model and considering the interaction between soil and structure,the dynamic load calculation formula of shallow buried frame structure under surface impact is derived,and the influence of structural flexibility on dynamic load of shallow buried structure on rigid foundation is analyzed.