【作者】 徐学勇；

【导师】 汪稔；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2009， 博士

【摘要】 钙质砂是分布于热带海洋中的一种特殊岩土介质,由于成因和组构上的特点导致其物理力学性质与常规的陆源砂有所区别。出于国防防卫和军事安全等方面的考虑,有必要开展钙质砂在爆炸荷载作用下动力响应特性研究,了解应力波在钙质砂中传播和衰减规律,探索饱和钙质砂的爆炸密实机理,为今后工程设计以及防御或减轻爆炸灾害提供基础性科研依据。论文以南沙群岛美济礁钙质砂为主要研究对象,采用室内小型爆炸试验、理论分析和数值模拟等研究方法,总结出饱和钙质砂在爆炸荷载作用下动响应特性以及爆炸应力波在钙质砂中传播和衰减规律,主要内容如下:1.回顾饱和砂土爆炸动力学研究历史和现状,基于应力波传播理论,分析了爆炸荷载作用下饱和砂土动力响应特征。2.通过室内小型爆炸试验,研究不同相对密度饱和钙质砂在不同类型爆炸荷载作用下土压力、孔隙水压力和质点振动加速度反应等参数的变化规律,总结出饱和钙质砂在爆炸荷载作用下动响应特性以及爆炸应力波在钙质砂中传播和衰减规律。3.进行饱和钙质砂室内爆炸密实试验,通过控制不同爆炸参数,对比分析不同参数下钙质砂试样爆炸前后密实效果的方法,探索饱和钙质砂的爆炸密实机理,研究不同爆炸作用参数下密实效果。4.进行相对密度40%和56%的石英砂小型爆炸试验,对试验结果进行分析,对比研究饱和钙质砂与石英砂在爆炸荷载作用下,爆炸动力响应特性和密实特性的差异。5.在有效应力分析方法的基础上,采用有效应力弹塑性本构模型,将模型编制成分析模块并与通用岩土工程分析软件FLAC接口。模拟分析爆炸应力波在饱和钙质砂中传播和衰减特性,并与试验结论进行对比。更多还原

【Abstract】 Calcareous sand is a special marine geotechnical medium,which has unexpected physical and mechanical property due to its origin and fabric.For the considerations of national defense and military security,there are needs to study on dynamic behavior of saturated calcareous soil due to explosion,study explosive wave propagation,explore saturated calcareous sand compacting mechanism of the explosion,which will provide basic scientific research satisitics for disaster proof and relief and the settlement of practical engineering problems.Taking Nansha islands calcareous sand as the object of the study,this paper has summarized dynamic behavior and explosive wave propagation of saturated calcareous soil through indoor mini-explosion test,theoretical analysis,numerical simulation and so on.The main points are as follows:1.Looking back the research history and present situation,the dynamic behavior of saturated soil due to explosion has been analyzed based on wave propagation theory.2.To study attenuation rules of earth pressure,pore pressure and acceleration in different relative density calcareous soil due to explosive load through indoor mini-explosion test.And then summarize dynamic behavior and explosive wave propagation of saturated calcareous soil.3.To explore compacting mechanism of the explosion and study compacting effects under different explosive parameter through indoor mini-explosive compacting experiment.4.To make comparative study of the dynamic behavior and compacting features between calcareous sand and ordinary sands through explosive experiment.In the experiment,two kinds of relative density of ordinary sand are chosen:40 percents and 56 percents.5.Based on effective stress analysis,the elastoplastic dynamic model of saturated sand is programmed and interfaced with the FLAC code.The characteristics of the propagation of stress wave in saturated sand under explosive loading is simulated and analyzed.更多还原