基于围岩稳定性与超前地质预报的高铁隧道钻爆开挖工法转换条件研究

发布时间：2018-01-15 03:27

本文关键词：基于围岩稳定性与超前地质预报的高铁隧道钻爆开挖工法转换条件研究　出处：《中国地质大学》2015年博士论文　论文类型：学位论文

【摘要】：自上个世纪60年代日本修建了世界上第一条现代化高速铁路开始,世界各国掀起了修建高速铁路的热潮,我国在2008年顺利开通时速350km/h的京津城际高速铁路,标志着我国进入高速铁路快速发展阶段。高速铁路的迅速铺开,自然无法避免在山岭区修建大量隧道,我国目前绝大多数山岭隧道的开挖均采用钻爆法,在采用钻爆法施工时,单一的开挖工法已经很难满足隧道安全施工的要求,随着隧道赋存地质条件的变化,所采取的开挖工法也需随之转换。但是目前我国极其缺乏高速铁路隧道钻爆开挖工法转换这一方面的理论研究,这就使得不同开挖工法之间的转换具有很大的主观性与经验性,选择不当或转换不及时,容易造成施工进度延误甚至发生隧道塌方事故。因此,开展高速铁路隧道钻爆开挖工法转换控制标准方面的研究具有重要理论价值和实践指导意义。以隧道钻爆开挖工法转换控制条件为研究中心,以沪昆客运专线长昆湖南段CKTJ-IX标段23条隧道共44个工作面的实际施工工况为依托,在国内外研究现状调研分析的基础上,首先阐述钻爆开挖工法的地层适宜性,并对研究区内各种钻爆开挖工法的应用效果进行评价；然后基于统计分析理论,对现场采集不同围岩等级、不同开挖工法下的围岩变形数据进行分析,研究隧道围岩变形位移、围岩变形时间以及围岩变形距离与围岩等级的关系,建立围岩-支护体系平衡稳定的评判标准。同时,基于围岩应力重分布的基本理论,从应力大小和应力方向的角度分析围岩三维变形特征,提出不同钻爆开挖工法下的围岩三维变形模式。在此研究成果上,定义围岩位移方向角；基于地层分界面两侧不同相对围岩强度、不同相对分布长度以及不同地层分界面倾角建立三维仿真地质模型,阐述隧道穿越地层分界面时围岩位移方向角的变化规律,并建立判定掌子面前方地质条件的标准,且提出一种预测掌子面前方地质条件的新方法；最后基于工法转换的前提条件,提出工法转换的原则以及工法转换条件的判定方法,建立工法转换控制体系。在理论研究的同时,将上述研究成果完整的应用在沪昆客运专线长昆湖南段姚家隧道和崔家冲隧道的工法转换实践之中,以验证研究成果的正确性与可行性。论文完成的主要工作包括以下几个方面：(1)对高速隧道钻爆开挖工法进行了全面的地层适宜性评价。依据本工程区段内工程地质条件,包括隧道埋深、地层岩性、地质构造、水文地质等,主要选用全断面开挖工法、上下台阶开挖工法、弧形导坑预留核心土开挖工法、三台阶七步开挖工法以及双侧壁导坑开挖工法等进行隧道的开挖掘进。首先从开挖工序、工艺特点和适用范围三个方面对开挖工法进行了全面介绍：其次依托各种开挖工法在现场应用的实际情况,从开挖工法的可行性、安全性、工期可控性以及经济性等五个方面进行工法适宜性评价。现场应用效果说明了隧道在开挖的过程中,合适的开挖工法不仅可以保障隧道的安全掘进,而且能最大限度的保证施工工期。因此,选择适宜的开挖工法对隧道的安全、进度、效益起着至关重要作用,隧道的开挖必须综合考虑各种因素并结合隧道的工程地质条件选择最优的开挖工法。(2)基于隧道围岩变形稳定的判定依据,结合现场23条隧道大量的围岩变形监测数据,提出了围岩变形的统计分析理论,并从定量的角度建立了围岩变形与围岩等级的关系以及时间-空间效应与围岩等级的关系。结论表明：围岩稳定位移、围岩稳定时间以及围岩稳定距离均与围岩等级近似呈线性关系,即随着隧道围岩等级的提高,围岩稳定位移不断增大、围岩稳定时间和围岩稳定距离不断增长。(3)以围岩稳定位移、围岩稳定时间以及围岩稳定距离作为判定围岩-支护体系平衡稳定的指标,并基于围岩变形监测数据的统计分析对各判定指标进行了量化,提出了各判定指标的建议值。然后以判定指标的建议值建立了围岩-支护体系的稳定基准线,并根据围岩稳定基准线对隧道围岩-支护体系的稳定性进行了判定,即当隧道围岩稳定判定指标量化值在基准线下方时,可判定隧道围岩变形处于常规发展状态,可正常施工；当隧道围岩稳定判定指标量化值处于基准线上下限之间时,可判定隧道围岩变形已进入基本稳定阶段,可按正常工序组织施工,必要时采取施工措施对围岩进行加强支护,控制围岩变形的持续发展；当隧道围岩稳定判定指标量化值在上限基准线上方时,可判定隧道围岩变形还未稳定,应立即预警并加大监测频率,查明原因后才能按正常程序组织施工。(4)基于围岩应力重分布的基本理论,提出了隧道在开挖的过程中,围岩应力分布的特征区域(稳定区域、掌子面受影响区域和未受影响区域),并阐述了每个特征区域的围岩变形表现形式；利用FLAC3D数值模拟软件分别建立了全断面开挖模型、上下台阶开挖模型、弧形导坑预留核心土开挖模型、三台阶七步开挖模型以及双侧壁导坑开挖模型,共5种开挖模型,然后从围岩应力大小和应力方向的角度,分析了各种开挖工法下的隧道围岩三维变形特征,并归纳了各种开挖工法下隧道拱部及边墙的围岩三维变形规律。在围岩三维变形规律的基础上,基于围岩裂隙扩展机理,提出了不同开挖工法下的4种围岩三维变形模式,分别为全断面开挖工法产生的竖向旋转至横向围岩变形模式、上下台阶开挖工法产生的纵向旋转至竖向围岩变形模式、弧形导坑预留核心土或者三台阶七步开挖工法产生的横向旋转至纵向围岩变形模式以及双侧壁导坑开挖工法产生的三个方向旋转变形模式。(5)采取了对隧道围岩的竖向变形和纵向变形同步进行监测的手段,并提出了隧道围岩位移方向角的概念,同时阐述了隧道在开挖过程中围岩位移方向角的变化规律,即无论掌子面处于均质硬岩或者均质软质,每个断面对应的位移方向角基本上相近,其相连而成的趋势线近似为一水平线,此时称之为常规状态。当掌子面离地质分界面较近或者即将穿越地质分界面时,隧道围岩的变形受到不同岩体的作用以及地质构造的影响,使得隧道围岩位移方向角偏离其常规状态,从而致使位移方向角趋势线产生较大的起伏,或正向或负向的变化。然后从地层分界面两侧围岩不同相对强度、围岩不同相对长度以及不同地层分界面倾角3个方面出发,分别建立了隧道由硬岩地层向软岩地层掘进的三维数值模型和隧道由软岩地层向硬岩地层掘进的三维数值模型,分析隧道在穿越地层分界面时,隧道围岩的竖向变形特征、纵向变形特征以及位移方向角变化规律,其结论可作为判定掌子面前方地质条件的一种方法。(6)采用高斯多峰拟合函数对围岩位移方向角变化规律进行了量化处理,并提出了以高斯多峰拟合曲线的拐点处一阶导函数值、峰值以及半高宽作为判定隧道掌子面前方地质条件的指标；利用判定指标的量化值建立了判定隧道掌子面前方相对围岩等级、相对分布长度以及地层分界面倾角的上下限基准线,即隧道在开挖的过程中,若判定指标的量化值在上下限基准线区间内,则可根据判定标准预测掌子面前方地质条件。(7)提出了隧道开挖工法转换的两个基本前提条件：第一确保隧道已开挖段围岩-支护体系的平衡稳定；第二准确预测掌子面前方地质条件。基于两个基本前提条件,提出了隧道开挖工法转换控制的总原则,即只有当判定指标的量化值在允许建议值的区间内,才可实施相应的工法转换。(8)分别提出了围岩-支护体系平衡稳定的判定方法和隧道掌子面前方地质条件的判定方法。针对围岩-支护体系平衡稳定的判定,提出了以一元非线性回归函数建立统计回归预测模型,然后利用该模型对隧道围岩变形进行预测,最后获取指标量化值进行判定的方法；针对掌子面前方地质条件的判定,提出了基于离散Frechet距离的高斯曲线相似度算法,对围岩位移方向角的高斯拟合曲线进行识别分群,然后获取指标量化值进行判定的方法。(9)以沪昆客运专线长昆湖南段CKTJ-IX标段内的姚家隧道和崔家冲隧道为例,采用本课题的研究成果,阐述了隧道由硬岩地层向软岩地层掘进时的工法转换实践和隧道由软岩地层向硬岩地层掘进时的工法转换实践；利用现场地质调查结果、实时围岩变形监测数据、声波测试试验及室内物理试验等方法进行了工法转换效果验证,其结果证明了开挖工法转换控制条件标准具有很好的可靠性与适用性。本文的创新成果主要有：(1)基于现场大量围岩变形监测数据,采用统计分析理论,从定量的角度建立了隧道拱顶下沉位移与围岩等级的关系、隧道周边收敛位移与围岩等级的关系、时间效应与围岩等级的关系以及空间效应与围岩等级的关系。提出了以围岩稳定位移、围岩稳定时间以及围岩稳定距离作为判定隧道围岩-支护体系平衡稳定的指标,并建立了围岩-支护体系平衡稳定的判定标准,为评价隧道围岩稳定性提供了一种新的手段。(2)基于围岩三维应力变化规律,阐述了不同开挖工法下的围岩三维变形模式。提出了围岩位移方向角的概念,并从地层分界面两侧围岩不同相对强度、不同相对分布长度以及不同地层分界面倾角三个方面出发,展示并归纳了围岩位移方向角的变化规律。(3)提出了以峰值函数中的高斯多峰函数对围岩位移方向角变化规律进行量化处理,以拟合曲线的拐点处一阶导函数值、峰值点以及半高宽作为判定隧道掌子面前方围岩相对强度、相对分布长度以及地层分界面倾角的指标,并建立了掌子面前方地质条件的判定标准,给出了各判定指标建议区间,为判定隧道掌子面前方地质条件提供了一种新的方法。(4)提出了隧道开挖工法转换的原则与条件,即第一确保隧道已开挖段围岩-支护体系的平衡稳定；第二准确预测掌子面前方地质条件。只要上述两个前提条件的判定指标量化值在建议区间内,则可实施工法转换。基于围岩稳定性与超前地质预报的高铁隧道钻爆开挖工法转换控制条件标准的研究成果,为隧道钻爆开挖工法选取、转换提供了理论支撑。
[Abstract]:Since the last century in Japan in 60s the world's first built a modern high-speed railway, the world set off the upsurge of the construction of high-speed railway in China, in 2008 the successful opening of Beijing Tianjin intercity high-speed railway speed of 350km/h, indicates that China has entered a stage of rapid development of high-speed railway. The rapid spread of high-speed railway, natural can not avoid the construction of a large number of tunnels in the mountain area, the excavation of the vast majority of our mountain tunnel by drilling and blasting method, the drilling and blasting method, single excavation method has been difficult to meet the requirements of the safety of the tunnel construction, with the change of the geological conditions of the tunnel excavation method, also need to be taken. But at present our country extremely the lack of high speed railway tunnel drilling and blasting theory research in this aspect of the conversion method of excavation, which makes the conversion between different excavation method has great and the subjective Experience, improper selection or conversion is not timely, easy to cause the construction delay and even accidents of tunnel collapse. Therefore, to carry out high-speed railway tunnel drilling has important theoretical value and practical significance of blasting excavation technique conversion control standard. The tunnel excavation method conversion control conditions for the research center, the Shanghai Kunming passenger dedicated line long Kun Hunan section CKTJ-IX section of 23 tunnels with a total of 44 working face based on the actual construction conditions, on the basis of investigation and analysis of the status quo at home and abroad, firstly expounds the formation for drilling and blasting excavation method, and the research area of all kinds of drilling blasting excavation engineering application effect evaluation; then based on the theory of statistical analysis. Collection of different surrounding rock grade on the scene, analyze the deformation data of surrounding rock under different excavation methods, study the deformation of tunnel surrounding rock displacement and deformation of surrounding rock and rock time The relationship between distance and deformation of surrounding rock mass grade, the establishment of surrounding rock supporting system stability criteria. At the same time, the basic theory of rock stress distribution based on the analysis from the three-dimensional deformation characteristics of surrounding rock stress and stress direction angle, put forward different blasting excavation method under three-dimensional deformation mode. This research results on the definition of rock displacement direction angle; based on two different relative strata interface strength of surrounding rock, different length and different relative distribution of strata interface angle establish 3D simulation geological model, changes of direction angle of displacement of surrounding rock tunnel through the strata boundary surface, and establish judgment in front of tunnel face geological conditions, and puts forward a new method forecast in front of tunnel face geological conditions; finally based on the premise of conversion method, the proposed method conversion principle and method of judging the conversion condition The method to establish method of conversion control system. At the same time, the application of the research results in the complete Shanghai Kunming passenger line length Kunming Hunan section of Yaojia tunnel and cuijiachong tunnel construction method and the feasibility of conversion practice, to verify the validity of research results. The main work of this thesis includes the following aspects: (1) blasting excavation method of strata suitability evaluation of high-speed tunnel drilling. According to the engineering geological conditions of the engineering section, including tunnel depth, lithology, geological structure, hydrogeology, mainly uses the full section excavation method, up-down excavation method, arc heading reservation core soil excavation method. Three step and seven step excavation method and double side excavation method of tunnel excavation. Firstly, from the excavation process, excavation method on three aspects of process characteristics and scope of application A comprehensive introduction: secondly relying on a variety of excavation method in practical application, the feasibility, the excavation method, the safety aspects of the five period, the controllability and economy of engineering suitability evaluation. Field application shows the tunnel during excavation, excavation safety method can not only guarantee the right of the tunnel moreover, to ensure the construction period to the greatest extent. Therefore, choosing suitable excavation method of tunnel safety, progress, efficiency plays a vital role, choose the optimal excavation method, the engineering geological conditions of tunnel excavation must consider various factors and combining with the tunnel. (2) the stability criterion of tunnel surrounding rock deformation based on combination the field monitoring data of surrounding rock deformation of 23 tunnels, proposes a statistical analysis theory of the deformation of surrounding rock, and the establishment of the surrounding rock deformation and rock from the quantitative point of view The relation and the relationship between the time - space effect and surrounding rock mass grade. Conclusion: stable displacement of surrounding rock, the surrounding rock stability time and the stability of surrounding rock and the surrounding rock grade distances are approximate linear relationship with the level of surrounding rock increases, the stable displacement of surrounding rock increases, the stability of the surrounding rock and the surrounding rock stability time of the growing distance (3). In order to stabilize the displacement of surrounding rock, the surrounding rock and the stability of surrounding rock stability time distance as the judgment of surrounding rock supporting system stability index, and based on the analysis of the index of quantitative statistics of monitoring data of surrounding rock deformation, the indexes of the recommended value. Then establish the stability of surrounding rock supporting system to determine the baseline index of the recommended values, and according to the reference line on the stability of surrounding rock stability of tunnel surrounding rock supporting system is determined, namely when the tunnel surrounding rock stability index quantization The value below the reference line, can determine the deformation of tunnel surrounding rock in the normal development of the state, the normal construction; when the tunnel surrounding rock stability index to quantify the value is between the reference line can determine the limit, has entered the stable stage of deformation of tunnel surrounding rock, according to the normal procedure organization construction, take necessary measures for construction of surrounding rock strengthening supporting sustainable development, control the deformation of surrounding rock; when the tunnel surrounding rock stability index to quantify the value of above in the upper reference line, can determine the deformation of tunnel surrounding rock is not stable, immediately warning and increase the frequency of monitoring, to identify the reasons according to the normal procedure of construction. (4) the basic theory of rock stress redistribution based on and put forward in the process of tunnel excavation, the surrounding rock stress distribution characteristics of the regional (stable region, face the affected and unaffected areas), and expounds the characteristics of each region Form the surrounding rock deformation domain; numerical simulation using FLAC3D software to establish the model of full section excavation, next step excavation model, arc heading reservation core soil excavation model, three step and seven step excavation model and double side excavation model, a total of 5 kinds of excavation model, then the stress and stress direction from the point of view the surrounding rock, analyzes various excavation of tunnel surrounding rock deformation characteristics under three-dimensional method, and summed up the excavation method under the arch of the tunnel and the side wall of the surrounding rock deformation. Based on three-dimensional 3D deformation of surrounding rock, the surrounding rock crack propagation mechanism based on the proposed 4 dimensional deformation pattern of different surrounding rock under excavation method, respectively. As a model of vertical deformation of surrounding rock is rotated to the transverse full section excavation method of longitudinal deformation pattern is rotated to the vertical rock excavation method produced on the next step, arc heading prepared The core soil or three step and seven step excavation mode and direction of the three side heading excavation method produces rotation deformation model method with deformation generated by lateral rotation to the vertical rock. (5) take the vertical to the tunnel surrounding rock deformation and longitudinal deformation of synchronous monitoring methods, and put forward the concept of tunnel surrounding rock displacement direction angle. The variation of tunnel surrounding rock in the excavation process of displacement direction angle, namely whether the face of hard rock in homogeneous or homogeneous soft, the direction of displacement in each section corresponds to the angle of basically similar, which is connected to the trend line is approximately a horizontal line, now called the conventional state. When the tunnel face off the interface is close to or is about to cross the geological geological interface, the deformation of the tunnel surrounding rock affected by different rock mass and geological structure, the tunnel surrounding rock displacement angle from the direction of The conventional state, resulting in greater fluctuation of displacement angle change trend line, or positive or negative. From then on both sides of the relative strength of different rock strata interface, surrounding rock with different relative length and different strata interface angle of 3 aspects, a 3D numerical model of tunnel by hard rock strata to the three-dimensional numerical model and tunnel excavation soft rock strata by soft rock strata to hard rock are established. The analysis of tunnel across strata interface, vertical deformation characteristics of surrounding rock of tunnel, longitudinal deformation characteristics and displacement direction angle change rule, the conclusion can be used as a method to determine the geological conditions in front of the face. (6) by Gauss the peak fitting function is used to quantify the regularity of surrounding rock displacement direction angle, and put forward the inflection point of Gauss multi peak fitting curve at the first derivative values, and the half width of peak As a judge in front of tunnel face geological conditions index; using quantitative index to judge the value of this paper in front of tunnel face relative grade of surrounding rock and relative distribution of length and angle of the upper and lower strata interface reference line, namely tunnel excavation process, if the index value of the quantization interval in the upper and lower reference line, then according to the criteria of prediction in front of tunnel face geological conditions. (7) proposed two basic conditions: the first method conversion of tunnel excavation to ensure tunnel has excavated section of surrounding rock supports stable supporting system; second accurate prediction in front of tunnel face geological conditions. Two basic conditions based on the proposed total tunnel excavation the principle of switching control method, that only when the index quantization value in the interval allowed value, can implement the corresponding conversion method. (8) are respectively proposed surrounding rock support Determination method of supporting decision method and in front of tunnel face geological conditions. According to the system balance and stability of surrounding rock and support decision support system stability, put forward to a linear regression function to establish the statistical regression model, and then to predict the deformation of tunnel surrounding rock by using the model, finally obtains the index quantization value judging method in front of the face; to determine the geological conditions, put forward the Gauss curve similarity algorithm based on the discrete Frechet distance, clustering recognition of Gauss curve displacement direction angle, and then get the method to determine the value of quantitative indicators. (9) to the Shanghai Kunming passenger line length Kunming Hunan section in CKTJ-IX section of Yaojia tunnel and the cuijiachong tunnel as an example, using the research results of this paper, elaborated the tunnel by hard rock excavation in soft rock strata to the engineering practice and the tunnel by soft switching Practice of the transformation of rock to hard rock strata of the excavation method; using the results of field geological investigation, rock deformation monitoring data real-time test and acoustic test, indoor physical test method to verify the effect of the conversion, the results show that the excavation method conversion control standard has good reliability and applicability. The innovation of this paper mainly include: (1) a large number of surrounding rock deformation monitoring data field based on the statistical analysis using the theory of relationship between tunnel and surrounding rock displacement level from a quantitative point of view is established, the convergence of the tunnel surrounding rock grade and displacement relationship, the relationship between time and effect and spatial effect of the rock grade and grade of rock mass was put forward. In order to stabilize the displacement of surrounding rock, the surrounding rock and the stability of surrounding rock stability time distance as determine the tunnel surrounding rock supporting system stability index, and the establishment of Wai Criteria of rock bolting system balance and stability, and provides a new method for the stability of tunnel surrounding rock evaluation. (2) rock 3D stress variation based on the exposition of the surrounding rock deformation mode under different 3D excavation method. Put forward the concept of the direction of displacement of surrounding rock angle, and from both sides of the rock strata interface, different relative the relative strength of different length and different distribution of the three aspects of dip strata interface, and summarizes the changes, showing the direction of displacement of surrounding rock angle. (3) proposed to peak function Gauss multi peak function rule of surrounding rock displacement direction angle is quantified, by fitting curve

【学位授予单位】：中国地质大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U455.4

【参考文献】