摘要
为使管棚受力分析模型能更好地模拟管棚的实际受力状态,基于注浆加固区域的受力特性分析,提出了考虑注浆加固区整体性的管棚受力分析模型。考虑注浆加固区的整体性,对管棚超前支护体系进行受力特性分析,提出可表征注浆加固区整体性的特征参数。综合考虑管棚注浆加固区整体性的特征参数、开挖面前方松动岩土体的支撑作用以及初期支护变形滞后效应等因素的影响,将管棚划分为二次衬砌段、初期支护段、开挖无支护段、开挖面前方扰动段和未扰动段;基于Winkler弹性地基模型,建立可考虑管棚注浆加固区整体性影响的管棚受力分析模型,并推导了管棚挠度和内力的计算公式。通过工程实例的对比分析,考虑注浆加固区整体性的管棚受力分析模型的计算结果更接近实测数据,从而验证了构建管棚模型的合理性。基于建立的管棚受力分析模型,分析注浆加固区的整体性对管棚变形和内力的影响规律,结果表明加固区弹性模量可显著减小管棚的变形和内力。管棚的参数分析表明,在实际工程中,增加钢管直径不能有效降低管棚挠度和内力,减小管棚挠度和内力最有效的方法为合理布置管棚的安装间距和采取合理的注浆量。
To make the analysis model of the pipe-roof better predict the actual stress state of the pipe shed,basing on the analysis the stress characteristics of the grouting reinforcement area,it was proposed that the stress analysis model of the pipe shed can consider the integrity of the grouting reinforcement area.The characteristic parameter that represents the integrity of the shell reinforcement area was proposed by analyzing the mechanical characteristics of the advanced support system.The pipe-roof was divided into four lining sections based on the integrity of the grouting reinforcement area,the supporting function of the loose rock and soil in front of the excavating surface,and the lag of the initial support deformation.These are the initial branch section,the no-supporting section,the disturbance section and the undisturbed section in front of the excavating surface.Based on Winkler elastic foundation model,the analytical model of the pipe-roof that takes into account the integrity of the grouting area of the pipe-roof was established,and the expressions for the deflection and internal force of the pipe-roof were derived.By comparison with engineering examples,the calculation results of the analytical model are found to be close to the measured data,which verifies the accuracy of the model.Based on the pipe-roof model,the effect of the grouting reinforcement zone integrity on the deformation and internal force of the pipe-roof was analyzed.The results demonstrate that the elastic modulus of the reinforcement zone can significantly decrease the deformation and internal force of the piperoof.The parameter analysis of the pipe-roof shows that increasing the diameter of the steel pipe has negligible effect in the reduction of the deformation and internal force.Further,a reasonable spacing and grouting amount are shown to reduce the deformation and internal force of the piperoof effectively.
作者
宋战平
田小旭
周冠南
李维维
SONG Zhan-ping;TIAN Xiao xu;ZHOU Guan-nan;LI Wei-wei(Department of Civil Engineering.Xi'an University of Architecture and Technology,Xi'an 71005,Shaanxi,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi'an 710055,Shaanxi,China;China Railway Major Bridge Engineering Group,Tianjin 300300,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2020年第4期89-98,共10页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51578447)
住房和城乡建设部科学技术项目(2017-K4-032)。
关键词
隧道工程
管棚
受力分析
加固区
整体性
弹性地基梁
tunnel engineering
pipe-roof
force analysis
pipe-reinforced area
integrity
elastic foundation beam
