摘要 强夯加固码头堆场地基时面临场地表层存在硬壳层、地基土均匀性差和区域性明显等问题,为了保证强夯合理施工及周边结构的安全,亟需对强夯地基振动规律进行研究。依托实际工程,系统研究了不同硬壳层厚度、不同强夯施工参数(夯锤半径、夯击数、夯击遍数)等条件下地基的振动规律。结果表明:1)在柱锤破壳阶段,硬壳层越厚,强夯振动峰值越大,且振速峰值随夯点距离的增加而减小,强夯区与建筑物之间的最小安全距离范围为37~58 m;2)在相同夯击能下,锤径越小,地基振动越剧烈,在满足地基加固效果的前提下,应优先考虑采用大锤径夯锤;3)在柱锤破壳阶段,振速峰值随夯击数增加而减小,当硬壳层贯通破坏后,夯击能被下卧软弱层吸收,振速峰值陡降;4)在平锤夯实阶段,振动峰值随夯击遍数的增加而增长,振速峰值增幅呈先增长后减小,最终趋于稳定的变化规律。 When the foundation of container terminal yard is reinforced by dynamic compaction,it is often faced with some problems,such as crust layer on the surface,poor uniformity and obvious regionality of foundation.In order to ensure the reasonable construction of dynamic compaction and the safety of surrounding structures,it is urgent to study the vibration regularity of foundation reinforced by dynamic compaction.based on the actual project,the vibration law of foundation under the conditions of different thickness of crust layer and different dynamic compaction construction parameters(such as the rammer radius,the number of tamping and times of tamping)was systematically studied.The results show that:1)In the stage of crust layer breaking by column hammer,the thicker the crust layer is,the greater the dynamic compaction vibration peak value is,and the peak value decreases with the increase of tamping point distance,the minimum safety distance between dynamic compaction area and surrounding buildings is 37-58 m;2)Under the same compaction energy,the smaller the hammer diameter is,the stronger the foundation vibration is,on the premise of satisfying the effect of foundation reinforcement,the large diameter rammer should be preferred;3)In the stage of crust layer breaking,the peak value of vibration velocity decreases with the increase of tamping number,when the crust layer is damaged,the tamping energy is absorbed by the underlying soft layer,and the peak value of vibration velocity decreases sharply;4)In the stage of flat hammer compaction,the peak value of vibration increases with the increase of tamping times,and the amplitude of peak value of vibration velocity increases at first and then decreases,and finally tends to be stable.
出处 《中国港湾建设》 2021年第4期32-35,71,共5页 China Harbour Engineering
关键词 硬壳层地基 强夯振动规律 安全距离 加固效果 crust layer foundation vibration law of dynamic compaction safety distance reinforcement effect
