多因素影响下石灰固化盐渍土抗剪性能的试验研究

发布时间：2018-10-24 21:03

【摘要】：北方地区季节性的冻融作用影响固化土的强度及变形特性。以冻融次数、含盐量、改性聚乙烯醇掺量(SH固土剂)、石灰掺量、养护龄期及干密度为影响因素,经正交试验设计及三轴UU压缩试验,获取固化盐渍土冻融后的抗剪强度及应力-应变性能。试验表明:试样冻融后的抗剪强度与改性聚乙烯醇掺量、石灰掺量、养护龄期和干密度呈正相关,与含盐量呈负相关;干密度和含盐量为影响固化盐渍土的黏聚力和内摩擦角的主要影响因素,冻融后土的抗剪强度逐渐降低,但抗变形能力逐渐增强,试样呈"鼓"型或弱脆性破坏;抗冻融效果最好的条件为:0.9%改性聚乙烯醇掺量与14%石灰掺量、干密度1.70 g/cm3、养护28 d、含盐量1%和冻融循环3次。
[Abstract]:Seasonal freeze-thaw effects on the strength and deformation characteristics of solidified soils in northern China. The factors affecting the freezing and thawing times, salt content, modified polyvinyl alcohol (SH), lime content, curing age and dry density were studied by orthogonal design and triaxial UU compression test. The shear strength and stress-strain properties of solidified saline soil after freezing and thawing were obtained. The results showed that the shear strength was positively correlated with the content of modified polyvinyl alcohol, lime, curing age and dry density, but negatively correlated with salt content. Dry density and salt content are the main factors affecting the cohesion and internal friction angle of solidified saline soil. The shear strength of frozen and thawed soil decreases gradually, but the deformation resistance is gradually enhanced, and the specimen is "drum" type or weak brittle failure. The optimum conditions for freeze-thaw resistance are as follows: 0.9% modified PVA and 14% lime, 1.70 g / cm ~ 3 dry density, 28 days curing, 1% salt content and 3 cycles of freeze-thaw cycle.
【作者单位】：天津城建大学地质与测绘学院;天津市软土特性与工程环境重点实验室;河北工业大学土木工程学院;
【基金】：国家自然科学基金项目(51409079) 河北省自然科学基金项目(E2014202104) 高等学校博士学科点专项科研基金(20131317120013) 天津市科技计划项目(152XCXSF00070,17JCZDJC39200,17JCYBJC22200)
【分类号】：TU448

【相似文献】