爆炸法处理深层软弱地基试验研究  

Test and Research of Blasting in Deep Soft Subgrade

作　　者：张志毅[1] 杨年华[1] 杨兵[1] 张翠兵[1] 

机构地区：[1]铁道科学研究院,北京100081

出　　处：《中国铁道科学》2002年第4期34-37,共4页China Railway Science

摘　　要：试验将袋装排水沙井、堆载预压和深部爆炸加载相结合 ,使深层软弱地基中的爆炸作用产生压实和快速排水固结 ,达到高效加固地基的目的。分析了现场爆炸处理地基试验过程中孔隙水压力变化过程、地表沉降量、触探试验值、土样物理力学性质指标和压缩空腔的变化。认为深部饱和土中爆炸后瞬时峰值压力很大 ,而且在很长一段时间内仍保持较高孔隙水压力值 ,能产生长达 3天的持久排水固结 ,与此同时地表沉降在爆后迅速发生 ,两次爆炸区的沉降量比一次爆炸大很多 ;由爆炸前后触探试验和土样物理力学性质实验对比 ,爆炸后土层强度指标有所提高 ,承载力提高 2 0 % ,压缩模量提高了 2 0 %。另外炮孔内空腔体积也扩大了 9倍。试验证明用爆炸法处理深层软弱地基是有效的、成功的。During the test sand wicks are prepared, piled up, pre pressed and at the same time blasting is conducted in deep underground to achieve quick consolidation of the drained ground and fast drainage of the water in soft ground. The paper analyzes the water pressure change in the porosities of the ground in question, the ground surface deposition, contact sensor values and geo sample physical mechanics nature, and the change of the pressed porosities. The paper holds that the instantaneous peak pressure value of the saturated earth after the blasting is very great and holds for a long time, as long as three day sustained draining and consolidation. The ground surface swiftly sink after the blasting. The level of sinking is greater in the case of popping blasts than that in one blast. The contact sensor test and the earth sample physical mechanics test before and after the blasting indicate that the ground layer intensity has increased and the bearing capacity has also increased by 20%. The blasting porosities have increased by 9 times. Test proves the deep blasting method used to treat the soft ground is effective and successful.

关 键 词：爆炸法 试验研究 软弱地基 孔隙水压力 排水固结 压缩空腔 地基处理 

分 类 号：TU472.9[建筑科学—结构工程] TU471.8[建筑科学—土工工程]