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Experimental Research on the Liquefaction Foundation Treatment Measures Used in the High Crack Earthquake Area Railway |
JIANG Chu—sheng1,LI Qing—hail1,HE Gang1,CAO Xin—wen2 |
1.China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China;2.Southwest Jiaotong University,Chengdu,Sichuan 610031,China |
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Abstract Research purposes:The Yuxi一Mengzi railway is through the tonghai lacustrine deposites basin. The main geological features are silty sand and silty clay. It is a typical seismic liquefaction foundation. Therefore,gravel一pile consolidation measures are applicated to reinforce the foundation. To demonstrate the feasibility of the compaction and drainage reinforcement,the dynamic tri一axial experimental study of liquefaction strength based on different sand density and drainage condition was performed.The pore water pressure of liquefaction foundation is effected by seismic intensity,which is simulated by shaking一terrace test. The liquefaction resistance of foundation was estimated by the change of pore pressure ratio.
Research conclusions:(1)By dynamic Tri一axial test and shaking一terrace test,the gravel一pile consolidation measures are effective reinforcement for the liquefaction foundation of tonghai basins.(2)The liquefaction resistance of silty sand and silty clay foundation has a significantly increase by the compaction and drainage effection of gravel一pile.(3)Under the seismic loading condition,the main liquefaction foundation area is out of embankment slope. The foundation of embankment has not liquefied,pore pressure ratio of which is much less than 0. 8. (4)For the foundation out of embankment slope,pore pressure ratio has increased rapidly when the liquefaction occurred.(5)For the liquefaction foundation,the reinforcement area is still need to be studied.(6)The liquefaction resistance of other reinforcement measures(Such as:cement一soil mixing piles,CFG piles,etc.)are needed to be further studied.(7)Shaking一isolated measures at toe of slope are recommended,and should be conducted a thorough study.
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Received: 10 May 2012
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