摘要
在富水砂层注浆加固工程中,浆脉对砂层的挤密作用对加固后的工作面稳定性和稳定时长具有控制性作用,注浆终压是形成挤密作用的关键参数,合理的注浆终压能够使注浆效果达到最佳,同时减少注浆量和地表抬升变形。选取青岛地区含黏性土砂层作为典型地层,采用一维排水固结压缩模拟浆脉挤密砂层过程,设计了一套测定渗透系数和稳定时长的试验装置,研究了渗透系数和稳定时长随固结压力的变化规律;并基于普氏自然平衡拱理论,验证了不同固结压力条件下砂层的稳定性。研究结果表明:当固结压力超过800 kPa时,固结压力的增加对砂层渗透系数及稳定时长的影响变得不显著;对于青岛地区标准单洞地铁隧道断面,当固结压力超过700 kPa时,可保证被挤密砂层的抗剪强度满足开挖自稳要求,因此,综合确定800 kPa为青岛地区该类富水砂层的合理注浆终压。研究成果应用于青岛地铁13号线灵-黄区间暗挖隧道富水砂层加固治理工程中,验证了理论成果的正确性,对浅埋暗挖隧道富水砂层灾害控制理论研究和工程实践具有一定指导意义。
In the grouting reinforcement project of water-rich sand layer, the compaction effect of the grout vein on sand layer controls the stability and stability-time of the strengthened working face. The final grouting pressure is a key parameter that determines compaction. A reasonable grouting final pressure can help achieve the best grouting effect while reducing the amount of grouting and surface uplift deformation. The cohesive soil sand layer in Qingdao area was selected as the typical stratum in this study. One-dimensional drainage consolidation compression was used to simulate the process of compacting the sand layer. The changing rules between the permeability coefficient and stability-time with respect to consolidation pressure were studied using the test device, which was specifically designed for determining the permeability coefficient and stable length. Based on the theory of natural equilibrium arch by Przewalskii, the stability of the sand layer under different consolidation pressure conditions was verified. The results of the study show that when the consolidation pressure exceeds 800 kPa, the influence of any increase in the consolidation pressure on the permeability coefficient and stable length of the sand layer is insignificant. For the section of the standard single-hole subway tunnel in Qingdao area, when the consolidation pressure exceeds 700 kPa, the shear strength of the compacted sand layer is guaranteed to meet the excavation self-stability requirements. Therefore, 800 kPa is comprehensively determined as the reasonable grouting final pressure of such water-rich sand layers in the Qingdao area. The research results were applied to the consolidation of water-rich sandstones in the Ling-Huang interval undercut tunnel of Qingdao Metro Line 13, which verifies the accuracy of these theoretical results. This work is thus significant in terms of the theoretical research and practical engineering applications that may help control water-rich sand disasters in shallow buried tunnels.
作者
姜鹏
张庆松
刘人太
刘亚南
张连震
JIANG Peng;ZHANG Qing-song;LIU Ren-tai;LIU Ya-nan;ZHANG Lian-zhen(Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,Shandong,China;School of Pipeline and Civil Engineering,China University of Petroleum,Oingdao 266580,Shandong,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2018年第10期302-310,共9页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51779133
51208294)
山东省自然科学基金项目(ZR2017MEE070)
关键词
隧道工程
富水砂层
室内试验
注浆加固
固结压力
稳定性
tunnel engineering
water-rich sand
laboratory test
grouting reinforcement
consolidation pressure
stability
