低含水率砂土和饱和砂土场地爆炸成坑特性实验

发布时间：2018-08-13 13:23

【摘要】：爆坑是土中爆炸荷载作用下的主要响应形式,基于大型爆炸实验场地,开展了一系列低含水率砂土和饱和砂土中的爆炸成坑现场实验,研究了药量、埋深及含水率等因素对土中爆坑效应的影响。研究结果显示:根据药包的比例埋深,低含水率砂土场地的最终爆坑形态可以分为隐爆、塌陷型漏斗坑和抛掷型爆坑3类,发生封闭爆炸的临界比例埋深为2.3m/kg1/3;形成抛掷型爆坑的条件为比例埋深小于1.5 m/kg1/3;当比例埋深为1.5~2.3m/kg1/3时,形成塌陷型漏斗坑。土中孔隙水压力的增大导致坑壁周围土体发生了液化流动、坍塌,最终造成爆坑横向尺寸的扩大。相同爆源条件下,饱和砂土场地形成的坑面直径比低含水率砂土场地提高了25%~35%,饱和砂土场地发生封闭爆炸的极限比例埋深可达2.5m/kg1/3。
[Abstract]:The explosion pit is the main response form under the action of explosion load in soil. Based on the large explosion test site, a series of field experiments of explosive pit formation in low moisture content sand and saturated sand are carried out, and the amount of explosive is studied. The effect of buried depth and moisture content on the effect of explosion pit in soil. The results show that according to the proportional burying depth of the charge, the final exploding pit shape of low moisture content sandy soil can be classified into three types: hidden explosion, collapsing funnel and throwing blasting pit. The critical burying depth of the closed explosion is 2.3 m / kg 1 / 3; the condition of forming the throwing blasting pit is that the proportional burying depth is less than 1.5 m / kg 1 / 3; when the proportional burying depth is 1.5~2.3m/kg1/ 3, the collapse type funnel is formed. The increase of pore water pressure in soil results in liquefaction flow and collapse of soil around the pit wall, resulting in the expansion of the transverse size of the crater. Under the same explosion source condition, the diameter of the pit surface formed by saturated sand site is 25% higher than that of low moisture content sand site. The limit ratio of closed explosion in saturated sand site can reach 2.5 m / kg 1 / 3.
【作者单位】：武汉市市政建设集团;宁波市交通建设工程试验检测中心有限公司;河海大学土木与交通学院;
【基金】：国家自然科学基金面上项目(51379067) 长江学者和创新团队发展计划项目(IRT1125)
【分类号】：TU43

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