| 砂性地层盾构隧道壁后注浆浆液扩散室内试验 |
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| 引用本文： | 蔡德国,叶飞,曹凯,杨鹏博,熊伟.砂性地层盾构隧道壁后注浆浆液扩散室内试验[J].中国公路学报,2018,31(10):274-283. |
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| 作者姓名： | 蔡德国 叶飞 曹凯 杨鹏博 熊伟 |
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| 作者单位： | 1. 西安市地下铁道有限责任公司, 陕西 西安 710018;2. 长安大学 公路学院, 陕西 西安 710064;3. 天津大学 建筑工程学院, 天津 300072;4. 中铁五局集团有限公司城市轨道交通工程分公司, 湖南 长沙 410205 |
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| 基金项目： | 国家自然科学基金项目（51478044，51678062） |
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| 摘 要： | 为了探明盾构隧道壁后注浆浆液扩散机理，基于对壁后注浆过程的分析，设计由试验模型箱、注浆系统、浆液配制系统、测试及数据处理系统组成的模型试验系统，试验前首先对水泥浆液的特性进行测试，然后通过该模型试验系统分别对3种不同级配的砂样地层（对应不同分维数）进行牛顿流体、宾汉姆流体、幂律流体的壁后注浆室内试验。根据试验结果分析注浆过程中浆液流速、土体密度及含水率的变化规律，并结合理论计算分析浆液的充填率λ，超挖系数和浆液压缩系数λ1+λ2，浆液损耗系数λ3，浆液在土体中的渗透系数及压密系数m的变化规律。结果表明：盾构隧道壁后注浆过程中，水灰比大小对浆液的流速、渗透扩散时间影响较大，砂样分维数对地层可注入时间的影响较为明显；浆液的充填率λ与水灰比大小有关，浆液损耗系数λ3 与水灰比呈正相关关系，不同砂样的超挖系数和浆液压缩系数λ1+λ2 的数值变化不大；浆液在砂样中的渗透系数及压密系数m与砂样的分维数呈负相关关系；3种不同的流体注浆结束后，管片周围土体的密度与土体所处的深度成反比，随着深度的增加，土体密度的变化率减小且纵向上的离散性降低；周围土体的含水率与土体所处的深度成正比，随着深度的变化，含水率的变化率亦减小且在纵向分布上趋于某一确定值。
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| 关 键 词： | 隧道工程 壁后注浆 模型试验 盾构 |
| 收稿时间： | 2018-02-01 |
Test of Grout Diffusion of Shield Tunnel Backfill Grouting in Sandy Strata |
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| CAI De-guo,YE Fei,CAO Kai,YANG Peng-bo,XIONG Wei.Test of Grout Diffusion of Shield Tunnel Backfill Grouting in Sandy Strata[J].China Journal of Highway and Transport,2018,31(10):274-283. |
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| Authors: | CAI De-guo YE Fei CAO Kai YANG Peng-bo XIONG Wei |
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| Affiliation: | 1. Xi'an Metro Ltd., Xi'an 710018, Shaanxi, China;2. School of Highway, Chang'an University, Xi'an 710064, Shaanxi, China;3. School of Civil Engineering, Tianjin University, Tianjin 300072, China;4. Urban Rail Traffic Engineering Branch Co., China Railway No.5 Engineering Group Co., Ltd., Changsha 410205, Hunan, China |
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| Abstract: | Grout diffusion of shield tunnel backfill grouting was investigated based on an analysis conducted for the construction phase. The experimental design included a test model box, grouting system, grout preparation system, and testing and data processing system. The properties of the grout were tested, and three kinds of sand strata with different gradations (in different fractal dimensions) were grouted using three different fluids based on model tests:Newtonian, Bingham, and power-law fluids. The regularity of variations in the grout flow velocity, soil density, and water content during the backfill grouting period were analyzed based on the test results. Combined with theoretical calculations, the regularity of variations in the grout filling ratio (λ), over-excavation coefficient and grout compression coefficient (λ1+λ2), grout loss coefficient (λ3), grout permeability coefficient, and compaction coefficient (m) in the soil were analyzed. The results show that the water cement ratio significantly influences the grout flow speed and diffusion time in the process of grouting, and the impact of the fractal dimension of the sand sample on the injectable time of the formation is pronounced. The grout filling ratio is related to the water cement ratio, and the grout loss coefficient is positively correlated with the water cement ratio. There is minor change in the over-excavation coefficient and grout compression coefficient values for the different sands. The grout permeability coefficient and compaction coefficient in soil are negatively correlated with the fractal dimension of the sand sample. After grouting with the three different fluids, the density of the surrounding soil is inversely proportional to the depth of the grouting hole. The rate of change of this density decreases and tends to have a low discreteness in the longitudinal direction. The water content of the surrounding soil is directly proportional to the depth of the grouting hole. The rate of change of this water content decreases and tends to be constant in longitudinal direction. |
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| Keywords: | tunnel engineering backfill grouting model test shield |
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