隧道地表高压旋喷加固的浆液渗透范围计算方法  

Method for calculating penetration range of grouting slurry in the reinforcedtunnel by high-pressure rotary jet grouting from ground

作　　者：徐华[1,2] 张瑜 郭国和 蔡敏 李奕信 陈壮 XU Hua;ZHANG Yu;GUO Guo-he;CAI Min;LI Yi-xin;CHEN Zhuang(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,Sichuan 610059,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Guangdong Yun Mao Expressway Co.Ltd,Guangzhou,Guangdong 510623,China;The 5th Engineer Co.Ltd.of China Railway 11th Bureau Group,Chongqin 400030,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [2]西南交通大学土木工程学院,四川成都610031 [3]广东云茂高速公路有限公司,广东广州510623 [4]中铁十一局集团第五工程有限公司,重庆400030

出　　处：《岩土力学》2023年第7期2064-2072,2128,共10页Rock and Soil Mechanics

基　　金：交通运输部重点科技项目(No.2019-MS1-017)。

摘　　要：由于隧道浅埋段软弱围岩地表高压旋喷加固后具有整体性好、强度高及渗透性低等优点,已被逐渐应用于实际工程,但高压旋喷浆液的渗透范围受到孔隙率、渗透路径及施工参数的影响难以确定。通过考虑岩土体性质、浆液流体力学特性及渗透路径等因素影响,基于圆孔扩张理论,建立浆液渗透范围的平面分析模型,推导出高压旋喷浆液的径向渗透范围计算公式,分析其适用范围及参数取值方法;结合现场开挖验证理论计算公式的可靠性,探讨影响浆液渗透范围的主控因素。研究表明:理论计算与现场实测的浆液渗透径向范围分别为成桩半径的0.630倍、0.618倍,两者相差仅2%,能较好地体现隧道浅埋段软弱围岩特性及各施工参数的影响;随岩土体孔隙率、浆液水灰比、旋喷压力的增大以及迂曲度的减小,浆液渗透范围呈增大的变化规律。该方法可为隧道软弱围岩地表高压旋喷加固的桩间距及桩径设计、加固效果评价等提供理论参考。Due to the advantages of good integrity,high strength and low permeability,surrounding rock reinforced by high-pressure rotary jet grouting in shallow buried section of tunnels has been gradually applied to practical engineering.However,the slurry penetration process is closely related to porosity,penetration path and construction parameters,thus it is difficult to determine the slurry penetration range.Through considering the properties of rock and soil,the hydrodynamic characteristics of grouting slurry and penetration path,a plane analysis model of slurry penetration range was established based on cavity expansion theory,and the calculation formula of radial penetration range of high-pressure rotary jet grouting was derived.Its application scope and parameter determination were also analyzed.Comparing with the field excavation,rationality of the theoretical formula was verified.Furthermore,the primary factors affecting the penetration range of slurry were discussed.The results show that the radial range of slurry permeation from theoretical formula and field measurement is 0.63 times and 0.618 times of pile radius,respectively,and the deviation of between theoretical permeation range and measured one is only 2%,which indicates that the proposed formula can well reflect the property of surrounding rock at shallow buried section of tunnels and the effect of construction parameters.The penetration filling range of high-pressure slurry increases with the increase of porosity,slurry water-cement ratio,rotary jet pressure and the decrease of tortuosity.The proposed method can provide theoretical basis for designing pile spacing and pile diameter,and for the evaluation of reinforcement effect on shallow buried section of tunnels using high-pressure rotary jet grouting.

关 键 词：隧道浅埋段 高压旋喷 圆孔扩张理论 浆液渗透范围 

分 类 号：U451[建筑科学—桥梁与隧道工程]