波浪作用下软黏土海床动力响应离心模型试验  

Centrifuge test on dynamic response of soft clay seabed under wave action

作　　者：吴雷晔 万佳怡 孔德琼[1,3] 朱斌[1,2] 陈仁朋[1,2] 陈云敏[1,2] WU Leiye;WAN Jiayi;KONG Deqiong;ZHU Bin;CHEN Renpeng;CHEN Yunmin(MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering,Zhejiang University,Hangzhou 310058,China;Institute of Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;Center for Hypergravity Experimental and Interdisciplinary Research,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058 [2]浙江大学岩土工程研究所,浙江杭州310058 [3]浙江大学超重力研究中心,浙江杭州310058

出　　处：《中南大学学报（自然科学版）》2022年第8期3040-3051,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52071289,51988101)。

摘　　要：利用自主研发的机载波浪模拟装置、采用摇板造波方式开展离心模型试验,对波浪作用下软黏土海床的动力响应问题进行研究。通过预试验确定最佳吸波参数,作为模型试验中降低边界效应的依据,对比海床表面实测波压力和理论值,验证该装置模拟海洋波浪的有效性。在离心加速度20g下进行离心模型试验,采用3次波浪加载测试软黏土海床在多次波浪作用和间歇期内的动力响应,观测海床内部孔压和强度以及海床表面的位移。研究结果表明:在循环波浪作用下,在软黏土海床1.4 m深以内,超静孔压达到初始竖向有效应力,该范围内土体强度大幅下降且随波浪产生流态化振荡;波浪导致的超静孔压在间歇期内(对应原型波浪15 d)无法完成消散;经多次波浪作用及重固结循环后,海床抵抗波致孔压累积的能力和不排水抗剪强度均明显提升。The dynamic response of soft clay seabed under wave action was investigated by centrifuge model tests using a flap type self-designed in flight wave generator. The optimum parameters for absorbing reflected waves were determined by preliminary tests to minimize the boundary effect. The performance of the wave-loading system was validated through comparisons of the wave pressure measured at the seabed surface with theoretical values. The dynamic response of soft clay seabed under wave action during wave loading and resting period was simulated using three wave trains at 20g. The development of wave-induced excess pore pressure, the undrained shear strength and the displacement of seabed were obtained. The results show that the wave-induced excess pore pressure reaches the initial vertical effective stress within the soil depth of 1.4 m, in which undrained shear strength of the soil decreases greatly and the surficial soil oscillates with waves. The wave-induced pore pressure cannot disappear completely during intermission of 15 d. After repeated wave action and reconsolidation cycles,both the resistance to wave loading of seabed and undrained shear strength are improved.

关 键 词：波浪作用 软黏土海床 离心模型试验 超静孔隙水压力 不排水抗剪强度 

分 类 号：TU43[建筑科学—岩土工程]