珊瑚礁砂与标准砂场地液化特征动力离心试验研究  

Dynamic centrifuge model test study on liquefaction characteristics of coral sand and standard sand

作　　者：陈平山[1,2] 梁小丛 王体强[3,4] 王德咏 王永志 樊旭[3,4] 陈卓识 袁晓铭[3,4] CHEN Pingshan;LIANG Xiaocong;WANG Tiqiang;WANG Deyong;WANG Yongzhi;FAN Xu;CHEN Zhuoshi;YUAN Xiaoming(CCCC Fourth Harbor Engineering Institute Co.,Ltd.,Guangzhou,Guangdong 510230,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,Guangdong 519082,China;Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin,Heilongjiang 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin,Heilongjiang 150080,China)

机构地区：[1]中交四航工程研究院有限公司,广东广州510230 [2]南方海洋科学与工程广东省实验室(珠海),广东珠海519082 [3]中国地震局工程力学研究所地震工程与工程振动重点实验室,黑龙江哈尔滨150080 [4]地震灾害防治应急管理部重点实验室,黑龙江哈尔滨150080

出　　处：《岩石力学与工程学报》2023年第9期2283-2294,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：南方海洋科学与工程广东省实验室(珠海)河口海岸与岛礁工程创新团队建设项目(311022013)。

摘　　要：珊瑚礁砂场地液化特性与抗液化处理措施是热带港口建设的关键问题之一。基于动力离心模型平行试验,从超静孔压、场地放大效应、地表沉降及反演分析剪切模量和阻尼比等方面,对比珊瑚礁砂和标准砂自由场地的地震液化特征。结果表明:相同条件下,珊瑚礁砂场地触发液化的荷载强度要显著高于标准砂场地,而液化深度明显小于标准砂场地。在0.2 g和0.3 g正弦波输入荷载下,珊瑚礁砂场地的加速度放大系数明显小于标准砂场地。0.05 g~0.3 g序列输入荷载下,珊瑚礁砂场地的累计地表沉降约为标准砂场地的2/3。场地液化后,珊瑚礁砂场地的剪应变要高于标准砂场地而剪应力小于标准砂场地。非液化土层,在0.2 g和0.3 g正弦波等强输入荷载下,珊瑚礁砂场地的剪应力和剪应变均小于标准砂。相同条件下,珊瑚礁砂场地的剪切模量随剪应变的衰减速率要快于标准砂场地。0.05 g~0.3 g序列输入荷载下,珊瑚礁砂场地的阻尼比均略小于标准砂场地。研究成果为认识珊瑚礁砂场地的液化特征和港口工程抗液化性态设计,提供了重要指导依据和丰富数据。The liquefaction characteristics and anti-liquefaction treatment measures of coral sand sites are one of the key issues in the construction of tropical ports.Based on the dynamic centrifuge model parallel test,the seismic liquefaction characteristics of coral sand and standard sand in free fields are analyzed from the aspects of excess pore water pressure ratio,site amplification effect,surface subsidence,shear modulus and damping ratio.The results show that the load intensity triggering liquefaction of coral sand site is significantly higher than that of standard sand site,and the liquefaction depth is significantly lower than that of standard sand site under the same conditions.The acceleration amplification coefficient of coral sand site is obviously smaller than that of standard sand under the loads of 0.2 g and 0.3 g sine wave.The cumulative surface subsidence of coral sand site is about 2/3 of that of standard sand site under 0.05 g–0.3 g sequence loads.In liquefied soil layer,the shear strain of coral sand site is higher than that of standard sand site and the shear stress is lower than that of standard sand site.In the non-liquefied soil layer,under the strong loads of 0.2 g and 0.3 g sine wave,the shear stress and shear strain of coral sand site are smaller than that of standard sand.The attenuation rate of shear modulus of coral sand site with shear strain is faster than that of standard sand site under the same conditions.The damping ratio of coral sand site is slightly smaller than that of standard sand site under 0.05 g–0.3 g sequence loads.The research results provide important guidance basis and rich data for understanding the liquefaction characteristics of coral sites and designing the anti-liquefaction behavior of port engineering.

关 键 词：土力学 珊瑚礁砂 动力离心试验 液化 放大效应 剪切模量 阻尼比 

分 类 号：TU41[建筑科学—岩土工程]