Influence of freezing after grouting on mechanical properties of fine sand based on low-temperature triaxial test(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年04期
- Page:
- 50-59
- Research Field:
- 冻土路基专栏
- Publishing date:
Info
- Title:
- Influence of freezing after grouting on mechanical properties of fine sand based on low-temperature triaxial test
- Author(s):
- YOU Xiao-feng; LIU Jian-kun; HU Xiang-dong; CHANG Dan
- 1. College of Civil Engineering, Tongji University, Shanghai 200092, China; 2. School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China
- Keywords:
- road engineering; fine sand; grouting; artificial ground freezing method; low-temperature triaxial test; mechanical property
- PACS:
- U416
- DOI:
- -
- Abstract:
- Partial deteriorated strength of frozen soil as well as frost heave and thaw subsidence were two main disadvantages of the artificial ground freezing method. The pregrouting method was regarded as a good supplement to the artificial ground freezing method to enhance the overall strength of fine sand ground and control the frost heave amount of ground after freezing. In view of pregrouting can effectively improve the strength and anti-permeability of soil, a series of indoor low-temperature triaxial shear tests were carried out and the effects of two experimental schemes, namely, freezing and freezing after grouting, on shear strength of fine sand were analyzed. Based on the analysis of fine sand strength improved by freezing after grouting, effects of cooling temperature, water-cement ratio, water content, curing time and lateral pressure on the strength and secant modulus at the peak of stress-strain curve were emphatically analyzed. The results show that the shear strength of sample increases with the decrease of cooling temperature and is proportional to water content, water-cement ratio as well as curing time, respectively. The grouted frozen samples always present higher secant modulus as expected with the decrease of cooling temperature and are proportional to water content, water-cement ratio and curing time. Besides, the cohesion c of fine sand reinforced by grouting and freezing shows a linear relationship with cooling temperature and an approximate exponential relationship with water-cement ratio and water content. Power function relationships are found among internal friction angle φ, cooling temperature and water content. There exists an exponential relationship between internal friction angle φ and water-cement ratio. This research provide references for the mechanical strength indices of fine sand reinforced by grouting and freezing, and guidance for the selection of water-cement ratio and curing time for artificial ground freezing projects.
Last Update: 2017-07-17