强夯振动测试与隔震处理效果分析

Analysis of Dynamic Compaction Vibration Test and Vibration Isolation Treatment Effect

通过现场监测的强夯振动测试数据,分析了在不同场地条件、不同能级强夯作用对土体的振动衰减规律、影响距离及振动主频等特征。同时进行了有、无隔震沟对振动波速峰值的影响性试验。试验结果表明,在3 000kN·m夯击能下,质点随振源距离的增大,振动速度逐渐减小,衰减速率也随之减小,质点的振动速度在50m范围内变化较大,超过这一距离趋于稳定;试验场地范围内最佳单击夯击数为5击;开挖隔振沟对振动波速的衰减效果明显,开口的隔振沟能够起到隔振减震的作用。隔振沟的深度越深,对振动波带阻隔的效果越好,为后续临近场地的设计、施工提出指导性的处理方案。并为类似地层的强夯设计与施工提供借鉴与指导。

Based on a dynamic compaction engineering example,the vibration data of dynamic compaction test on site was compared.The vibration law of surrounding soil under different conditions of dynamic compaction was analyzed.The influence of the factors of the energy level of dynamic compaction,the compaction number and the distance of measuring point on vibration velocity,acceleration and frequency of vibration was compared.In addition,the effect that whether there was the isolation groove or not on the peak value of the vibration wave velocity in two cases was studied.The results show that,under two different site conditions,the tendency of vibration attenuation of dynamic compaction tends to be similar,which verifies the universality of vibration attenuation of dynamic compaction.The optimum number of compaction tests for this project is 5 strokes and the influence range of vibration is 50 m.The influence of various factors on the decay rate of vibration velocity is obtained,and the beneficial effect of vibration isolation groove on vibration reduction is verified.By summarizing the vibration rules of dynamic compaction,a reference and guidance for the dynamic compaction design and construction of similar strata is provided.