饱和砂土分层地基爆炸液化引起的地表沉降特征分析  

Analysis of Surface Settlement Characteristics caused by Explosion-induced Liquefaction of Saturated Sand Layered Foundation

作　　者：位需贝 卢文波[1,2] 王高辉[1,2] WEI Xu-bei;LU Wen-bo;WANG Gao-hui(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of Ministry of Education,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072 [2]武汉大学水工岩石力学教育部重点实验室,武汉430072

出　　处：《爆破》2023年第2期9-19,共11页Blasting

基　　金：国家自然科学基金(51939008、52179140);湖北省自然科学基金杰出青年项目(2021CFA093)。

摘　　要：饱和砂土地基爆炸液化引起的地表沉降问题是坝基抗震安全评价和爆炸加密地基处理等领域中的重要课题。针对碾压压实的分层饱和砂土地基,研究其在封闭爆炸下液化引起的地表沉降特征。基于现有爆炸液化、地表沉降经验预测模型推导了液化区体积的计算式,建立了地表沉降区的快速预测模型,并验证了该模型的可靠性。利用上述模型,通过变化控制性因素密实度、炸药量、埋深探究了饱和砂土地基爆炸液化区及引起的地表沉降漏斗特征,并讨论了地基碾压压实分层对地表沉降漏斗特征的影响。结果表明:封闭爆炸荷载作用下,饱和砂土地基爆炸液化区的形态从小到大包括椭球型、漏斗型和锅底型三种。地表沉降区形态从小到大有倒锥型和蝶型两种。液化及沉降区随炸药量的增加、埋深和密实度的减小而增大。经碾压压实的分层饱和砂土地基,爆炸液化及引起的地表沉降不仅受炸药量、埋深和密实度的影响,分层厚度较起爆深度的相对大小也决定了液化区受分层厚度影响的范围,进一步影响了地表沉降区的范围。Ground surface settlement caused by explosion-induced liquefaction of saturated sand foundation is an important subject in the seismic safety evaluation and explosion compaction of dam foundation.In this paper,the characteristics of ground surface settlement caused by liquefaction under contained explosions are studied for layered saturated sand foundation with roller compaction.Based on the existing empirical prediction models of explosion-induced liquefaction and surface settlement,the calculation formula of liquefaction volume is derived,and the rapid prediction model of surface settlement area is established and verified for reliability.Based on the above model,the characteristics of the explosion-induced liquefaction zone of saturated sand foundation and the resulted surface settlement funnel are investigated by changing the control factors such as compactness,explosive amount and burial depth,and the influence of stratified ground compaction on the characteristics of the surface settlement funnel is also discussed.The results show that the explosion liquefaction zone of saturated sand foundation has three types from small to large,including ellipsoid type,funnel type and pot bottom type.From small to large,there are two types of surface settlement area:inverted cone type and butterfly type.The liquefaction and settlement zones increase with the increase of explosive amount and the decrease of burial depth and compactness.For the layered saturated sand foundation with rolling compaction,the explosion-induced liquefaction and the resulted surface settlement are not only affected by the amount of explosive,buried depth and density,but also determined by the relative size of delamination thickness compared with the initiation depth,which further affects the range of surface settlement area.

关 键 词：分层地基 爆炸液化 超孔隙水压比 液化区特征 沉降漏斗特征 

分 类 号：TU478[建筑科学—结构工程]