强夯地震效应特征研究

强夯是一种较好的地基处理方法,目前已获得广泛的应用,但强夯引起的地震效应对周边一定范围内的建筑物有一定程度的影响,由强夯施工引发的民事纠纷时有发生,因此,深入研究强夯地震效应的特征,对于合理设计强夯施工方案,避免对周围建筑物造成损坏有积极意义。根据《爆破安全规程》的有关规定,采用振动速度作为研究工作的主要物理量。收集了广东省工程防震研究院近几年来在广东省内承担的 10 项地基强夯处理时的地震效应测试资料,并在施工中有针对性地增加了一些测试内容,通过对这些资料的分析、整理和研究得出了关于强夯地震效应特征的3个结论。

Study of Earthquake Effect of Dynamic Compaction

This paper analyses the monitoring data of earthquake effects of dynamic compaction obtained from 10 project sites in Guangdong province. It is shown that the vibration of earthquake caused by dynamic compaction is mainly in vertical direction, thus the vertical vibration could be chosen as the criterion for evaluating the degree of vibration damage. The velocity of vibration resulted from dynamic compaction follows V=K(QR)~α,in which K and α are the factor and attenuation exponent related to the site condition, with values of 2.22～3.76 and 1.15～2.30 respectively. The frequency of vibration caused by dynamic compaction is dependent upon the site condition: the softer the ground, the lower the main frequency; the longer distance the vibration travels, also the lower the main frequency. Generally, the dominant frequency of vibration caused by dynamic compaction is less than 10 Hz, posing potential damages to low houses.