饱和砂土场地大型爆炸液化现场试验研究

土体振动液化是岩土工程领域中引人注目的热点问题,振动及液化引发的房屋倒塌或堤坝溃决将严重危及生命和财产安全。基于室外大型爆炸液化可控试验场地,开展了一系列饱和砂土中的单点及多点微差爆炸液化试验。介绍了现场爆炸液化试验的主要技术细节,包括钻孔及布药方式、监测设备及方法、混凝土结构及土质堤坝的设计等。分析了饱和砂土中单点和多点微差爆炸引起的土中孔隙水压力上升规律、爆炸液化的影响因素以及利用多点微差爆炸液化人工制造大面积液化试验场地的实现条件和方法,并最终开展爆炸液化场地混凝土结构及土质堤坝的变形研究。试验的成功实施为人工制造大型振动液化试验场地的方法提供了参考。

Large-scale field tests on blast-induced liquefaction in saturated sand

The vibration-induced liquefaction in soils is a notable hottopic in geotechnical engineering. The building collapse and embankment burst induced by liquefaction are fatal for the loss of lives and properties of human beings. A series of blasting tests including single explosive charge and multiple underground blasts with millisecond delays are conducted in a large-scale field site filled with saturated sand. The methods of borehole drilling and charge burying, monitoring equipment, design of concrete structure and embankment, and other technical details about blast-induced liquefaction are introduced. The liquefaction mechanism produced by single shallow-buried detonation or multiple blasts is studied firstly. Then the influence factors on the blast-induced liquefaction are analyzed. Based upon these results, the method to produce a large area of liquefaction condition is determined. Finally, the stability of a concrete structure and a soil-embankment on the liquefaction ground is discussed. The successful implementation of blast-induced liquefaction tests can provide references for artificially producing large-scale liquefaction environment.