超大断面小净距隧道施工围岩空间变形与荷载释放机制及工程应用
发布时间：2018-07-25 09:37
【摘要】：随着经济社会的发展和城市化建设步伐的加快,交通拥堵已经成为制约城市和区域发展的重要因素,原有的两车道、三车道公路已经无法满足日益增长交通流量的需要,一部分山区高速公路和市区快速路的建设已经进入新的发展时期,与此对应的超大断面隧道的建设也呈现出快速增多的趋势。但是国内外超大断面公路隧道的工程实践尚不多见,既无成熟的施工建设经验可以借鉴,也无可靠的计算方法可以使用,更无设计、施工的规范和标准可参考,仅能依靠为数不多的简单的工程类比进行分析。本文针对超大断面公路隧道施工工序受力复杂、围岩稳定性判别基准不确定、荷载计算方法不明确以及支护结构和参数选取难度较大等研究现状及难题,通过理论分析、室内试验、模型试验、数值模拟以及现场试验等手段,结合济南东南二环延长线项目在建港沟隧道工程实际,深入研究了超大断面隧道施工过程中围岩空间变形和荷载释放规律,并对超大断面隧道的施工方法比选和净距优化进行了详细研究,取得了一系列具有理论价值和工程意义的研究成果,主要包括:(1)针对影响隧道围岩应力特征的净距、矢跨比、侧压力系数等因素,分别从应力集中度的角度对超大断面小净距隧道的围岩力学特征进行了分析总结。结合现有普式压力理论和公路隧道设计规范,对超大断面小净距隧道围岩压力及荷载模式进行了探讨,在考虑超大断面小净距隧道施工过程中先行洞和后行洞相互影响的前提下,分别进行了浅埋情况和深埋情况下的超大断面小净距隧道围岩压力计算方法和公式的推导。通过公式分析研究可得,超大断面小净距隧道内侧围岩与外侧围岩的压力呈不对称的偏压分布,中夹岩墙竖向围岩压力大于隧道外侧,先行洞由于受后行洞开挖扰动的影响,偏压程度较后行洞更加严重。根据该模式进行计算,可以得到更加安全合理的隧道支护结构设计参数,对类似工程的设计具有一定的借鉴意义。(2)开展了工程现场的围岩动态分级评价和点荷载试验,并对白云质灰岩开展了室内试验,既对现场施工提供了动态指导,又对模型试验和数值模拟围岩参数的选择提供了依据。借鉴以有相似材料配制经验,在"正交试验设计,敏感因素分析"的前提下,进行了流-固耦合相似材料的配制,并在模型试验中成功应用。在节省试验开支的前提下,研制了厚壁方管组合式试验台架和降雨模拟系统,构建了多元信息实时监测和采集系统。利用激光相位测量技术,融合空间动态坐标测量方法与虚拟测量技术,进行了适用于模型试验围岩变形测量的柔性点云数据测量仪的研发,实现了地质力学模型试验开挖轮廓测量的高自动化、高适应性、柔性、非接触、高效的优点,可同时将扫描路径三维正交分解,通过计算及距离测量自动获得最佳测量轨迹,可实现对多种隧道模型,多种开挖部形状的快速精密测量。针对该仪器基于MATLAB进行了后处理软件的开发,可以将柔性点云数据测量仪采集的隧道模型点云数据进行降噪、抽稀、拟合处理,再对比两次测量数据计算隧道的变形量,对隧道模型变形信息进行空间可视化的提取。(3)选取依托工程现场有代表性里程段,以此为原型开展了超大断面隧道浅埋小净距段施工过程模型试验研究和复杂地层超大断面隧道施工过程力学模型试验研究,对超大断面浅埋小净距隧道施工过程及降雨入渗对围岩空间变形的影响规律进行了研究,同时对穿越断层破碎带前后不同开挖工法施工下围岩的空间变形及荷载释放规律进行了探讨。针对模型试验所选取的工程原型施工段,开展了相应数值模拟试验研究,通过两者结果的相互验证,增加了结果的可靠度。其结果对揭示超大断面浅埋小净距隧道施工过程中围岩空间变形机制,确保该复杂地层段的施工安全,保证隧道顺利贯通提供了支撑。(4)修正了已有的摩尔-库伦屈服接近度,并基于弹塑性有限差分数值模拟,进行了超大断面小净距隧道围岩稳定性影响因素的分析和评价,对不同围岩等级的隧道给出了合理的施工方案建议。研究了超大断面小净距隧道施工力学特征,对小净距隧道围岩变形分布规律和施工的空间变形效应进行了分析和探讨,建立了超大断面小净距隧道合理净距优化准则,并提出了不同围岩级别隧道最小净距的合理取值。(5)依托四车道超大断面小净距港沟隧道,对其施工过程中围岩和支护结构体系的力学特点及规律进行了监测研究,并对其施工过程中的时空效应进行了分析总结。并据此对依托工程的小净距段支护参数和支护方案进行了优化设计,对提高施工质量及进度,确保施工安全,保证隧道的顺利贯通具有一定的指导意义。
[Abstract]:With the development of economic and social development and the accelerated pace of urbanization, traffic congestion has become an important factor restricting the development of cities and regions. The original two lane and three lane highways have been unable to meet the needs of increasing traffic flow, and the construction of some mountainous expressways and urban expressway has already entered a new development period. The construction of the super large section tunnel is also increasing rapidly. However, the engineering practice of super large section highway tunnel at home and abroad is still few, no mature construction experience can be used for reference, no reliable calculation method can be used, no design, the standard and standard of application can be referred, only can rely on the number of not. Many simple engineering analogies are analyzed. In this paper, the research status and problems of the construction procedure of super large section highway tunnel are complicated, the criterion of stability discrimination of surrounding rock is not definite, the calculation method of load is not clear, and the difficulty of selecting the support structure and parameters is more difficult, through the theoretical analysis, indoor test, model test, numerical simulation and the analysis of the construction process. By means of field test and so on, combining with the project of Ji'nan southeast second ring extension line in the construction of Jian Gang tunnel project, the space deformation and load release law of the surrounding rock during the construction process of the super large section tunnel are deeply studied, and the construction method and net distance optimization of the super large section tunnel are studied in detail, and a series of theoretical values have been obtained. The main achievements of the research are as follows: (1) in view of the factors affecting the stress characteristics of the tunnel surrounding rock, the factors such as the spacing, the vector span ratio, the side pressure coefficient and so on, the mechanical characteristics of the surrounding rock of the super large section small distance tunnel are analyzed and summarized respectively from the angle of stress concentration. The pressure and load mode of large section and small spacing tunnel are discussed. Under the premise of considering the interaction between the first tunnel and the rear row tunnel during the construction process of the super large section and small distance tunnel, the calculation method and formula of the surrounding rock pressure of the tunnel with a small net distance under the shallow burial situation and the deep buried condition are derived respectively. It can be concluded that the pressure of the inner wall rock and the outer surrounding rock of the tunnel with the small spacing of the super large section is asymmetrical, and the pressure of the vertical surrounding rock of the medium wall rock wall is larger than the outside of the tunnel. The deviation degree is more serious because of the influence of the opening and excavation of the tunnel under the influence of the opening and excavation of the tunnel. The design parameters of the tunnel supporting structure are of certain reference significance to the design of similar engineering. (2) the dynamic classification evaluation and the point load test of the surrounding rock of the engineering site are carried out, and the indoor test is carried out on the dolomitic limestone, which not only provides dynamic guidance to the site construction, but also selects the selection of the parameters of the model test and the numerical simulation of the surrounding rock. In the premise of "orthogonal test design, sensitive factor analysis", a flow to solid coupling material was prepared and successfully applied in the model test. On the premise of saving the test expenses, the thick wall square tube assembly test bench and rainfall simulation system were developed, and a multiple letter was constructed. The research and development of a flexible point cloud data measuring instrument, which is suitable for the deformation measurement of the surrounding rock of the model test, has been developed by using the laser phase measurement technology, the spatial dynamic coordinate measurement method and the virtual measurement technology, and the high automation, high adaptability, flexibility and non performance of the excavation contour measurement of the geomechanical model test are realized. With the advantages of contact and high efficiency, the three-dimensional orthogonal decomposition of the scanning path can be obtained at the same time, and the optimal measurement trajectory can be obtained automatically through the calculation and distance measurement. It can realize the rapid and precise measurement of various tunnel models and the shape of various excavations. The flexible point cloud data measuring instrument can be collected by the development of the post processing software based on the MATLAB. The tunnel model point cloud data of the set is de-noising, thinning, fitting and processing, and then comparing the deformation of the tunnel with two measurements, and extracting the spatial visualization of the deformation information of the tunnel model. (3) the representative mileage section of the engineering site is selected as the prototype, so as to open the construction of the shallow distance section of the super large section tunnel for the construction of Guo Chengmo. The model test research and the mechanical model test on the construction process of the super large section tunnel in complex strata are studied. The influence law of the construction process and the rainfall infiltration on the space deformation of the surrounding rock is studied, and the spatial deformation and load release of the surrounding rock under the construction of different excavation methods before and after the crossing fault fracture zone are carried out. According to the prototype construction section selected by the model test, the corresponding numerical simulation test was carried out, and the results were verified by the mutual validation of the two results. The results showed that the deformation mechanism of the surrounding rock in the construction process of the shallow and small distance tunnel in the super large section was revealed, and the application of the complex formation section was ensured. The work safety provides support for the smooth passage of the tunnel. (4) modified the existing mole Kulun yield proximity, and based on the elastoplastic finite difference numerical simulation, the analysis and evaluation of the influence factors of the stability of the surrounding rock of the tunnel with small distance and small spacing are carried out. The reasonable construction proposal is given to the tunnel with different surrounding rock. The mechanical characteristics of the super large section and small distance tunnel construction are analyzed. The distribution law of the surrounding rock deformation and the spatial deformation effect of the small net distance tunnel are analyzed and discussed. The optimization criterion of the reasonable spacing of the tunnel with the small spacing of the super large section is established, and the reasonable distance of the minimum net distance of the tunnel with different surrounding rock grade is put forward. (5) relying on the super break of the four lane. The mechanical characteristics and rules of the surrounding rock and support structure system in the construction process are monitored and studied. The spatio-temporal effect of the construction process is analyzed and summarized. The optimization design is made for the support parameters and support schemes of the small net distance section relying on the project, and the quality and progress of the construction are improved. It is instructive to ensure the safety of construction and ensure the smooth operation of the tunnel.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U456.31
，
本文编号：2143398
[Abstract]:With the development of economic and social development and the accelerated pace of urbanization, traffic congestion has become an important factor restricting the development of cities and regions. The original two lane and three lane highways have been unable to meet the needs of increasing traffic flow, and the construction of some mountainous expressways and urban expressway has already entered a new development period. The construction of the super large section tunnel is also increasing rapidly. However, the engineering practice of super large section highway tunnel at home and abroad is still few, no mature construction experience can be used for reference, no reliable calculation method can be used, no design, the standard and standard of application can be referred, only can rely on the number of not. Many simple engineering analogies are analyzed. In this paper, the research status and problems of the construction procedure of super large section highway tunnel are complicated, the criterion of stability discrimination of surrounding rock is not definite, the calculation method of load is not clear, and the difficulty of selecting the support structure and parameters is more difficult, through the theoretical analysis, indoor test, model test, numerical simulation and the analysis of the construction process. By means of field test and so on, combining with the project of Ji'nan southeast second ring extension line in the construction of Jian Gang tunnel project, the space deformation and load release law of the surrounding rock during the construction process of the super large section tunnel are deeply studied, and the construction method and net distance optimization of the super large section tunnel are studied in detail, and a series of theoretical values have been obtained. The main achievements of the research are as follows: (1) in view of the factors affecting the stress characteristics of the tunnel surrounding rock, the factors such as the spacing, the vector span ratio, the side pressure coefficient and so on, the mechanical characteristics of the surrounding rock of the super large section small distance tunnel are analyzed and summarized respectively from the angle of stress concentration. The pressure and load mode of large section and small spacing tunnel are discussed. Under the premise of considering the interaction between the first tunnel and the rear row tunnel during the construction process of the super large section and small distance tunnel, the calculation method and formula of the surrounding rock pressure of the tunnel with a small net distance under the shallow burial situation and the deep buried condition are derived respectively. It can be concluded that the pressure of the inner wall rock and the outer surrounding rock of the tunnel with the small spacing of the super large section is asymmetrical, and the pressure of the vertical surrounding rock of the medium wall rock wall is larger than the outside of the tunnel. The deviation degree is more serious because of the influence of the opening and excavation of the tunnel under the influence of the opening and excavation of the tunnel. The design parameters of the tunnel supporting structure are of certain reference significance to the design of similar engineering. (2) the dynamic classification evaluation and the point load test of the surrounding rock of the engineering site are carried out, and the indoor test is carried out on the dolomitic limestone, which not only provides dynamic guidance to the site construction, but also selects the selection of the parameters of the model test and the numerical simulation of the surrounding rock. In the premise of "orthogonal test design, sensitive factor analysis", a flow to solid coupling material was prepared and successfully applied in the model test. On the premise of saving the test expenses, the thick wall square tube assembly test bench and rainfall simulation system were developed, and a multiple letter was constructed. The research and development of a flexible point cloud data measuring instrument, which is suitable for the deformation measurement of the surrounding rock of the model test, has been developed by using the laser phase measurement technology, the spatial dynamic coordinate measurement method and the virtual measurement technology, and the high automation, high adaptability, flexibility and non performance of the excavation contour measurement of the geomechanical model test are realized. With the advantages of contact and high efficiency, the three-dimensional orthogonal decomposition of the scanning path can be obtained at the same time, and the optimal measurement trajectory can be obtained automatically through the calculation and distance measurement. It can realize the rapid and precise measurement of various tunnel models and the shape of various excavations. The flexible point cloud data measuring instrument can be collected by the development of the post processing software based on the MATLAB. The tunnel model point cloud data of the set is de-noising, thinning, fitting and processing, and then comparing the deformation of the tunnel with two measurements, and extracting the spatial visualization of the deformation information of the tunnel model. (3) the representative mileage section of the engineering site is selected as the prototype, so as to open the construction of the shallow distance section of the super large section tunnel for the construction of Guo Chengmo. The model test research and the mechanical model test on the construction process of the super large section tunnel in complex strata are studied. The influence law of the construction process and the rainfall infiltration on the space deformation of the surrounding rock is studied, and the spatial deformation and load release of the surrounding rock under the construction of different excavation methods before and after the crossing fault fracture zone are carried out. According to the prototype construction section selected by the model test, the corresponding numerical simulation test was carried out, and the results were verified by the mutual validation of the two results. The results showed that the deformation mechanism of the surrounding rock in the construction process of the shallow and small distance tunnel in the super large section was revealed, and the application of the complex formation section was ensured. The work safety provides support for the smooth passage of the tunnel. (4) modified the existing mole Kulun yield proximity, and based on the elastoplastic finite difference numerical simulation, the analysis and evaluation of the influence factors of the stability of the surrounding rock of the tunnel with small distance and small spacing are carried out. The reasonable construction proposal is given to the tunnel with different surrounding rock. The mechanical characteristics of the super large section and small distance tunnel construction are analyzed. The distribution law of the surrounding rock deformation and the spatial deformation effect of the small net distance tunnel are analyzed and discussed. The optimization criterion of the reasonable spacing of the tunnel with the small spacing of the super large section is established, and the reasonable distance of the minimum net distance of the tunnel with different surrounding rock grade is put forward. (5) relying on the super break of the four lane. The mechanical characteristics and rules of the surrounding rock and support structure system in the construction process are monitored and studied. The spatio-temporal effect of the construction process is analyzed and summarized. The optimization design is made for the support parameters and support schemes of the small net distance section relying on the project, and the quality and progress of the construction are improved. It is instructive to ensure the safety of construction and ensure the smooth operation of the tunnel.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U456.31
，
本文编号：2143398
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