夯实水泥土桩-网复合地基工作性状对比试验研究

Comparative experimental study on working behavior of rammed cement-soil pile-net composite foundation

为了探讨夯实水泥土桩-网复合地基的工作性状,开展有、无土工格栅条件下夯实水泥土桩9桩复合地基模型的静载对比试验,分析有、无土工格栅对夯实水泥土复合地基的承载力、平均沉降量、桩-土沉降差、桩-土应力比及桩顶应力的影响。研究结果表明：在夯实水泥土桩复合地基的垫层内加入土工格栅后,地基承载力特征值提高约27.9%,桩-土平均沉降差减小56.5%-62.7%,桩–土应力比提高60.9%-70.8%,且各桩的受力更加均匀,有利于复合地基中桩体承载性能的发挥;当地基处理工程中遇到上部荷载较大或对地基沉降要求较高时,可在夯实水泥土桩复合地基的垫层内增设土工格栅来改善地基处理效果。

In order to study the working behavior of rammed cement-soil pile-net composite foundation, contrast static load tests of composite foundation with or without geogrids were performed, and each foundation model contained nine piles. The influences of geogrids on average pile-soil settlement difference, pile-soil stress ratio and the stress of top piles were analyzed. The results show that with geogrids in rammed cement-soil pile composite foundation, characteristic value of bearing capacity increases by approximately 27.9%,the average pile-soil settlement difference reduces by56.5%-62.7%, the pile-soil stress ratio increases by 60.9%—70.8%, and the pile head stress is more even, which can promote the bearing behavior of piles in composite foundation. When ground treatment encounters comparatively larger load or higher settlement requirements that rammed cement-soil pile composite foundation can not meet the requirements,geogrids can be added to improve the treatment effect.