摘要
跨江河大桥的大量兴建对既有航道的影响日益凸显,船撞桥梁的事故频繁发生.受损桥梁修复与加固所需要的支护平台施工对受损桥梁产生的扰动影响程度如何?有无安全性问题?这些均为处理受损桥梁亟待解决的问题.结合磨刀门特大桥船撞事故修护工程中临时支护平台桩基沉桩施工的实际案例,分析了振冲沉桩施工扰动对地基土及邻近受损桥梁的影响.根据爆破安全规程(GB6722—2014)和中国地震烈度表(GB/T 17742—2008),以最大速度容许值作为判据得到了桩基振动施工的影响范围;基于小孔扩张理论分析了施工振动的挤土效应,并综合考虑给出了临时支护平台振冲沉桩施工的最小安全距离容许值为11m;运用数值模拟非线性时程分析,针对实际工程确定了合理的激振力参数,建议激振力振幅A不大于300kN、激振力频率f不小于10Hz,为解决此类工程问题提供一种新思路和方法.
The massive construction of the bridge across the river has an increasingly prominent impact on the existing waterway.Ship collision with bridge frequently occurs.What is the influence of temporary support platform construction for repairing and strengthening the damaged bridge on the disturbance of the damaged bridge?Is there a security issue?All of them are urgent problems to be solved to deal with the damaged bridge.Based on the practical case of the vibroflotation pile construction with the temporary support platform in the ship collision repairing project of Maodaomen large bridge,the influence of the construction disturbance of vibroflotation pile on the foundation soil and the adjacent damaged bridge is analyzed.According to the Safety Regulations for Blasting(GB 6722—2014)and the Chinese Seismic Intensity Scale(GB/T 17742—2008),the influence range of pile foundation vibration construction is obtained by taking the maximum allowable velocity value as the criterion.Based on the cavity expansion theory,the compaction effect of construction vibration is analyzed,and the minimum safe distance allowable value of 11 m for the vibration construction of temporary supporting platform pile foundation is given.Based on the nonlinear time-history analysis of numerical simulation,reasonable excitation force parameters are determined for practical engineering.It is suggested that the excitation force amplitude A should not be greater than300 kN and the excitation force frequency f should not be less than 10 Hz.It provides a new idea and method for solving this kind of engineering problem.
作者
董芸秀
冯忠居
冯凯
王蒙蒙
唐博学
DONG Yunxiu;FENG Zhongju;FENG Kai;WANG Mengmeng;TANG Boxue(School of Highway,Chang’an University,Xi’an 710064,China;School of Civil Engineering,Longdong University,Qingyang 745000,China;Guangdong Provincial ChangDa Highway Engineering Co.,Ltd.,Guangzhou 510620,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2020年第4期981-992,共12页
Journal of Basic Science and Engineering
基金
广东省交通科技攻关项目(JP-YS-A21-2014-325)
关键词
岩土工程
振冲沉桩
激振力
挤土效应
影响范围
geotechnical engineering
vibrotation pile
excitation force
compaction effect
influence range
