考虑封孔浆体黏度时空变化的止浆机制研究
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摘要
封孔止浆技术是松软地层注浆防渗加固的重要手段,而封孔浆体自下而上的注入方式及其黏度时变特性导致浆体在止浆段长内黏度呈现出空间分布不均匀。通过流变试验获取封孔浆体流变参数与流型,建立考虑黏度时空变化的宾汉流体同心环状劈裂封孔浆体止浆模型,推导出黏度时空变化的封孔浆体止浆的控制方程,并定量分析封孔浆体的止浆能力,最后将研究成果成功应用于河堤防渗加固注浆工程。研究结果表明,封孔浆体黏度时空变化对浆体封孔止浆能力影响较大,其止浆能力与浆体流变参数、浆体塑性强度、封孔高度等有关;封孔浆体所能承受的极限注浆压力随封孔浆体固化剂掺量的增加或封孔浆体塑性强度的增大而增大,且这种变化随封孔高度的增高而表现的越明显,综合考虑注浆堵管、后续拔管等问题,封孔浆体水固比宜控制在1∶1左右,且黏土含量不宜超过50%,固化剂掺量宜控制在1.2%～1.8%;现场钻孔取样、压水试验均反映注浆后地层连续性和整体性得到了显著提高,已达到设计防渗加固标准,理论计算推导虽与实测结果存在一定误差,但可满足实际工程要求。研究结果有利于封孔浆体止浆技术的进一步推广应用,可为工程实践提供理论指导。
The borehole sealing technique is an important method for anti-seepage and grouting reinforcement of soft soil strata. However, the bottom-up injection method and the time-varying characteristics of viscosity will cause the viscosity of sealing slurry to present a nonuniform spatial distribution in through range. The rheological parameters and flow patterns of the sealing slurry are obtained through rheological tests. The sealing model for concentric annular fracturing sealing slurry of Bingham fluid is established considering the temporal and spatial variation of viscosity, and the relevant governing equations are deduced. The sealing capacity of slurry is quantitatively analyzed, and the research results are successfully applied to the anti-seepage and grouting reinforcement of a levee. The results show that the temporal and spatial variation of viscosity of slurry has a great influence on its sealing capacity which is related to the rheological parameters of slurry, plastic strength of slurry and height of borehole. The ultimate grouting pressure of the sealing slurry increases with the increasing amount of curing agent or its increasing plastic strength and such phenomenon is obviously reflected with the increasing height of borehole. Considering the issues of grouting plugging and pipe pulling, the water-solid ratio of the sealing slurry should be controlled to be about 1:1, the clay content should not exceed 50%, and the content of curing agent should be controlled in the range of 1.2% to 1.8%. The on-site borehole sampling and pump-in tests show that the continuity and integrity of the soil strata are significantly improved after grouting and the anti-seepage reinforcement standards are achieved. Although the theoretical derivations have certain errors with the measured results, they can conform to the actual engineering requirements. The research results are conducive to the further application of the slurry sealing technique, and they may provide theoretical guidance for engineering practice.
The borehole sealing technique is an important method for anti-seepage and grouting reinforcement of soft soil strata. However, the bottom-up injection method and the time-varying characteristics of viscosity will cause the viscosity of sealing slurry to present a nonuniform spatial distribution in through range. The rheological parameters and flow patterns of the sealing slurry are obtained through rheological tests. The sealing model for concentric annular fracturing sealing slurry of Bingham fluid is established considering the temporal and spatial variation of viscosity, and the relevant governing equations are deduced. The sealing capacity of slurry is quantitatively analyzed, and the research results are successfully applied to the anti-seepage and grouting reinforcement of a levee. The results show that the temporal and spatial variation of viscosity of slurry has a great influence on its sealing capacity which is related to the rheological parameters of slurry, plastic strength of slurry and height of borehole. The ultimate grouting pressure of the sealing slurry increases with the increasing amount of curing agent or its increasing plastic strength and such phenomenon is obviously reflected with the increasing height of borehole. Considering the issues of grouting plugging and pipe pulling, the water-solid ratio of the sealing slurry should be controlled to be about 1:1, the clay content should not exceed 50%, and the content of curing agent should be controlled in the range of 1.2% to 1.8%. The on-site borehole sampling and pump-in tests show that the continuity and integrity of the soil strata are significantly improved after grouting and the anti-seepage reinforcement standards are achieved. Although the theoretical derivations have certain errors with the measured results, they can conform to the actual engineering requirements. The research results are conducive to the further application of the slurry sealing technique, and they may provide theoretical guidance for engineering practice.
引文
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[7]盛松涛,张贵金,陈安重.托口水电站河湾地块帷幕灌浆新工艺的施工实践[J].水利水电技术,2014,45(8):108-111.(SHENG Song-tao,ZHANG Gui-jin,CHEN An-zhong.Construction practice of a new curtain grouting technology for river-bending block in site of Tuokou Hydropower Station[J].Water Resources and Hydropower Engineering,2014,45(8):108-111.(in Chinese))
[8]张贵金,梁经纬,杨东升,等.松软地层脉动灌浆封孔浆体止浆机制初步研究[J].岩土工程学报,2016,38(2):210-218.(ZHANG Gui-jin,LIANG Jing-wei,YANG Dong-sheng,et al.Mechanism of stemming slurry materials for pulsating grouting in soft strata[J].Chinese Journal of Geotechnical Engineering,2016,38(2):210-218.(in Chinese))
[9]李术才,刘人太,张庆松,等.基于黏度时变性的水泥-玻璃浆液扩散机制研究[J].岩石力学与工程学报,2013,32(12):2415-2421.(LI Shu-cai,LIU Ren-tai,ZHANGQing-song,et al.Research on C-S slurry diffusion mechanism with time-dependent behavior of viscosity[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2415-2421.(in Chinese))
[10]李术才,韩伟伟,张庆松,等.地下工程动水注浆速凝浆液黏度时变特性研究[J].岩石力学与工程学报,2013,32(1):1-7.(LI Shu-cai,HAN Wei-wei,ZHANG Qing-song,et al.Research on time-dependent behavior of viscosity of fast curing grouts in underground construction grouting[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(1):1-7.(in Chinese))
[11]阮文军.基于浆液黏度时变性的岩体裂隙注浆扩散模型[J].岩石力学与工程学报,2005,24(15):2709-2714.(RUAN Wen-jun.Spreading model of grouting in rock mass fissures based on time-dependent behavior of viscosity of cement-based grouts[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(15):2709-2714.(in Chinese))
[12]李术才,张伟杰,张庆松,等.富水断裂带优势劈裂注浆机制及注浆控制方法研究[J].岩土力学,2014,35(3):746-748.(LI Shu-cai,ZHANG Wei-jie,ZHANG Qing-song,et al.Research on advantage-fracture grouting mechanism and controlled grouting method in water-rich fault zone[J].Rock and Soil Mechanics,2014,35(3):746-748.(in Chinese))
[2]冯海明.止浆塞在浅层覆盖型岩溶灌浆工程中的应用[J].岩土工程技术,1998,2(1):1-3.(FNEG Hai-ming.Application of grouting plug in covered karst grouting project[J].Geotechnical Engineering Technology,1998,2(1):1-3.(in Chinese))
[3]梁为,王海鹏,尹尚先.胶囊式分段注浆止浆塞的研制[J].煤炭工程,2011(3):114-116.(LIANG Wei,WANGHai-peng,YIN Shang-xian.Research and development of packer for capsule type stage grouting[J].Coal Engineering,2011(3):114-116.(in Chinese))
[4]夏可风.孔口封闭灌浆法讨论[C]//《水工建筑物水泥灌浆与边坡支护技术》暨第9次水利水电地基与基础工程学术会议.贵阳,2007:10-20.(XIA Ke-feng.Grouting method for orifice closed discussions[C]//《Hydraulic Structure Cement Grouting and Technology of Slope Support》and Conference Foundation of Water Conservancy and Hydropower Engineering on 9th.Guiyang,2007:10-20.(in Chinese))
[5]张贵金,许毓才,陈安重,等.一种适合松软地层高效控制灌浆的新工法-自下而上、浆体封闭、高压脉动灌浆[J].水利水电技术,2012,43(3):38-41.(ZHANG Gui-jin,XUYu-cai,CHEN An-zhong,et al.A new technical method for efficient and control grouting for loose ground-high pulsating pressure grouting from bottom to up stemming with slurry[J].Water Resources and Hydropower Engineering,2012,43(3):38-41.(in Chinese))
[6]张贵金,增柳絮,陈安重,等.松软地层高压灌浆封孔浆体研制及应用论证[J].岩土工程学报,2012,34(6):1110-1116.(ZHANG Gui-jin,ZENG Liu-xu,CHEN An-zhong,et al.Development and application demonstration of stemming slurry materials for high pressure grouting in soft stratum[J].Chinese Journal of geotechnical Engineering,2012,34(6):1110-1116.(in Chinese))
[7]盛松涛,张贵金,陈安重.托口水电站河湾地块帷幕灌浆新工艺的施工实践[J].水利水电技术,2014,45(8):108-111.(SHENG Song-tao,ZHANG Gui-jin,CHEN An-zhong.Construction practice of a new curtain grouting technology for river-bending block in site of Tuokou Hydropower Station[J].Water Resources and Hydropower Engineering,2014,45(8):108-111.(in Chinese))
[8]张贵金,梁经纬,杨东升,等.松软地层脉动灌浆封孔浆体止浆机制初步研究[J].岩土工程学报,2016,38(2):210-218.(ZHANG Gui-jin,LIANG Jing-wei,YANG Dong-sheng,et al.Mechanism of stemming slurry materials for pulsating grouting in soft strata[J].Chinese Journal of Geotechnical Engineering,2016,38(2):210-218.(in Chinese))
[9]李术才,刘人太,张庆松,等.基于黏度时变性的水泥-玻璃浆液扩散机制研究[J].岩石力学与工程学报,2013,32(12):2415-2421.(LI Shu-cai,LIU Ren-tai,ZHANGQing-song,et al.Research on C-S slurry diffusion mechanism with time-dependent behavior of viscosity[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2415-2421.(in Chinese))
[10]李术才,韩伟伟,张庆松,等.地下工程动水注浆速凝浆液黏度时变特性研究[J].岩石力学与工程学报,2013,32(1):1-7.(LI Shu-cai,HAN Wei-wei,ZHANG Qing-song,et al.Research on time-dependent behavior of viscosity of fast curing grouts in underground construction grouting[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(1):1-7.(in Chinese))
[11]阮文军.基于浆液黏度时变性的岩体裂隙注浆扩散模型[J].岩石力学与工程学报,2005,24(15):2709-2714.(RUAN Wen-jun.Spreading model of grouting in rock mass fissures based on time-dependent behavior of viscosity of cement-based grouts[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(15):2709-2714.(in Chinese))
[12]李术才,张伟杰,张庆松,等.富水断裂带优势劈裂注浆机制及注浆控制方法研究[J].岩土力学,2014,35(3):746-748.(LI Shu-cai,ZHANG Wei-jie,ZHANG Qing-song,et al.Research on advantage-fracture grouting mechanism and controlled grouting method in water-rich fault zone[J].Rock and Soil Mechanics,2014,35(3):746-748.(in Chinese))