就地固化设计参数对软土地基承载特性影响的现场试验研究

Field test and research on influence of in-situ curing design parameters on bearing characteristics of soft soil foundation

为深入研究就地固化技术设计参数对软基加固效果的影响,开展固化剂掺量和养护龄期对加固后软土地基承载特性影响的现场试验研究。试验区1(固化剂掺量)划分为100 kg/m^(3)、120 kg/m^(3)、130 kg/m^(3)、140 kg/m^(3)和160 kg/m^(3)等5个试验区,处理深度为2.5 m,待养护7 d进行载荷试验;试验区2(养护龄期)采用固化剂掺量160 kg/m^(3),处理厚度2 m的方案,分别在养护14 d和28 d后进行载荷试验。通过研究得到以下主要结论:固化后软土地基的承载力随固化剂掺量增加而提高。就地固化加固软土地基存在130 kg/m^(3)的临界固化剂掺量。当固化剂掺量小于临界掺量,载荷试验时地基发生隆起破坏,变形模量很小;当固化剂掺量超过临界掺量,载荷试验时地基承载力增加且不会发生破坏,变形模量随固化剂掺量增加而提高。就地固化后软土地基的承载能力和变形模量随养护龄期的增加而提高。

In order to study the influence of design parameters of in-situ curing technology on the reinforcement effect of soft soil,the field test study on the influence of dosage of curing agent and curing age on the bearing characteristics of soft soil foundation after soil improvement was carried out.Test Area 1 (for dosage of curing agent) was divided into 5 sub-test areas(100 kg/m^(3),120 kg/m^(3),130 kg/m^(3),140 kg/m^(3),160 kg/m^(3)).The treatment depth of Test Area 1 was 2.5 m,and loading test was carried out after curing of 7 days.A dosage of curing agent of 160 kg/m^(3)was used in Test Area 2 (for curing age) and the thickness of improvement was 2.0 m,and the loading test was carried out after curing of 14 days and 28 days respectively.The results show that the bearing capacity of solidified soft soil increased with the increase of dosage of curing agent.There is a critical dosage of curing agent of 130 kg/m^(3)in the in-situ solidification of soft soil foundation.When the dosage of curing agent is less than the critical dosage,the foundation uplift failure occurred during the loading test.When the dosage of curing agent exceeds the critical dosage,the bearing capacity of the foundation increases and does not develop failure.When the dosage of curing agent is less than the critical dosage of curing agent,the deformation modulus is very small.When the dosage of curing agent is greater than the critical dosage of curing agent,the deformation modulus is improved with the increase of dosage of curing agent.The bearing capacity and deformation modulus of soft soil foundation after in-situ curing increases with the increase of curing age.