【作者】 张良刚；

【导师】 吴立；

【作者基本信息】 中国地质大学 ， 岩土工程， 2014， 博士

【摘要】 近年来我国特大断面隧道和地下工程大量涌现,尤其是在客运专线中较为突出。为了克服客运专线高速列车在隧道内运行所引起的空气动力学问题,特大断面高速铁路隧道的应用逐渐增加,这些隧道轨面以上的净空面积在100m2以上,开挖断面积在150m2以上。特大断面隧道的建设相比常规尺寸隧道的建设在隧道的力学行为、断面形式、衬砌结构、施工方法、初期支护结构模式、支护参数等方面提出了新的要求。隧道围岩变形特征受地质条件、设计参数、施工技术及管理等诸多因素的影响,且影响程度各不相同。随着大断面隧道的应用逐年增多,目前国内外学者针对大断面隧道围岩变形做了一些研究,但在理论研究和工程实践方面仍存在一些不足之处,主要表现为：①工程上对大变形还没有明确统一的定义,同时勘察设计、施工各方认识不统一；②研究角度的多样性导致研究成果的局限性;③运用系统性的测试方法和手段进行的综合研究比较少。在工程实践中,预测将会发生大变形的地段,支护设计进行了加强,但在实际施工过程未出现大变形；预测没有大变形的地段发生了大变形,给工程施工带来困难。大量文献研究结果显示,围岩大变形问题己经成为地下工程世界性的难题之一,尤其是在对特大断面隧道施工期围岩变形特征以及控制技术方面,缺乏相关的文献资料。论文以沪昆客运专线长昆湖南段Ⅸ标段馒子湾隧道为依托,选题来源于湖北省自然科学基金重点项目“软质板岩特大断面隧道围岩-支护系统流变变形控制机理研究”(基金编号：2013CFA110),并结合“沪昆客专长昆湖南段隧道超前地质预报与监控量测”的专题研究,开展特大断面板岩隧道围岩变形特征与控制技术研究。论文从板岩围岩工程特性出发,运用理论分析、现场试验(监控量测)和数值模拟等方法研究特大断面板岩隧道在不同施工方法和支护方式下的围岩力学特征和变形破坏规律,分析了围岩变形影响因素和变形机理,并建立了有效预测特大断面板岩隧道围岩变形的PSO-SVM模型,对隧道大变形的预防和控制意义重大；同时运用收敛约束法对初期支护状况进行分析研究,结合相应理论分析计算出围岩特征曲线和支护特征曲线,对特大断面板岩隧道初期支护的适用性进行评价以及提出隧道支护结构的最优组合,并从围岩控制原则和技术体系中提出相应的控制措施,对工程设计和施工具有重要的指导意义。论文完成的工作包括以下几个方面：1.特大断面板岩隧道围岩工程特性试验研究(1)通过现场地质调查、资料收集及工程地质报告,对所研究区区域的地质背景和工程地质条件做了较详细地阐述,分析了研究区的地形地貌、地层岩性、地质构造、水文地质和地应力场等特征。(2)通过单轴和三轴压缩试验,研究了干燥状态不同结构面倾角下板岩的力学特性,得出：①板岩的泊松比在0.15～0.25之间浮动,且与结构面和加载方向的夹角之间关系不密切；②在相同围压条件下,板岩的单轴抗压强度和弹性模量在不同结构面倾角下先由大变小,减小到一定值后,再逐渐增大。③通过拟合,得出三轴压缩强度σ和弹性模量E与结构面和加载方向的夹角α之间的关系。(3)通过三轴压缩试验,研究了干燥状态不同围压下板岩的力学特性,得出：①在一定范围内,其应变随应力的增加呈现直线增加,而当应力达到峰值以后,试件突然破坏,应力急剧减小,而侧向应变迅速增大；②试验结果表明：围压对板岩强度影响较大,抗压强度随围压的增加呈现线性增加趋势。(4)干燥状态下板岩的破坏特征如下：①单轴压缩时,主要发生剪切破坏和顺层面滑动破坏；②当结构面倾角与轴力方向垂直时,不同围压作用下,试件破坏主要以剪切破坏为主,随着围压的增加,破坏面与最大主应力的夹角逐渐增大,且破坏面越来越平整。(5)研究了不同含水状态且围压为10MPa时板岩的力学特性,得出：①随着浸水时间的增加,其抗压强度和弹性模量都呈减小的趋势,而泊松比却增大；②浸泡后其应力应变曲线在达到峰值前存在一定的塑性屈服段,峰值后出现应变软化段,且随着泡水时间的增加,峰值前塑性屈服与峰值后应变软化段愈明显。(6)基于模糊综合评判法对Hoek-Brown强度准则的扰动系数进行修正,进而计算出研究区域板岩的岩体力学参数。通过与经验值法、张建海修正法以及声波测试法计算结果对比分析得出,论文提出的基于模糊综合评判法修正的扰动系数与声波测试法计算出的扰动系数值较接近,表明基于模糊综合评判法修正Hoek-Brown强度准则的扰动系数的合理性,解决了采用声波测试法费用高和难以实施的困难,可为类似的工程提供参考应用。(7)干燥状态下,采用分级加载时,每级荷载作用下,板岩的轴向和侧向都会发生瞬时应变与蠕变应变,其中瞬时应变大约占整个变形的80%,且轴向应变较侧向应变变形大,约为2-3倍。(8)轴向应力的大小对岩体的蠕变变形特性有着至关重要的影响,当轴向应力小于岩体的屈服应力时,其侧向应变与轴向应变呈线性增加关系；当轴向应力大于岩体的屈服应力时,其侧向与轴向应变呈指数关系变化。(9)不同含水状态下,围压为15MPa时,其蠕变规律与干燥状态下相似,且随着含水率的增加,其轴向变形量和侧向变形量依次增加。(10)在总结经典蠕变模型的基础上,通过分析对比,论文采用修正的Burgers模型计算研究区域的蠕变参数,为后续的数值计算分析奠定基础。2.特大断面板岩隧道围岩变形特征分析(1)介绍了馒子湾隧道监控量测技术及其数据处理方法,结合馒子湾隧道监控量测数据,对隧道洞口处地表沉降以及在不同隧道开挖方法(三台阶七步开挖法、弧形导坑预留核心土法和台阶法)下围岩变形随时间的变化规律进行分析。(2)隧道出口地表横向沉降呈中央值很大的正态分布规律,隧道拱顶轴线方向上沉降最大,两侧的沉降随着距离的增大而减小,且随着隧道埋深的增大,地表的累计沉降量依次减小。当隧道掌子面开挖到地表监测点时,该监测点可能发生隆起或者下沉现象；但当隧道掌子面穿越地表监测点后,由于隧道断面支护闭合的作用,大约距离掌子面W-2D(D为洞径)时,地表沉降开始收敛。(3)通过绘制围岩变形-时间特征曲线,对不同开挖方法下围岩变形随时间的变化规律进行了分析,得出围岩变形-时间特征曲线。(4)通过拟合对比分析,指数函数是论文研究区域围岩变形特征分析的最佳拟合函数。其中函数y=a(1-e-e-ht)适用于拱顶沉降和上测线收敛变形分析,而函数y=ae-b/t分析下测线收敛变形时精度更高。(5)三种工法下围岩变形的径向释放率在相同时间内拱顶最小,其次是上测线,下侧线最大。各断面开挖30天后径向变形释放率就接近100%,趋于稳定。(6)结合馒子湾隧道监控量测资料,针对不同围岩级别,对围岩变形和距掌子面距离的关系进行了分析,得出：①围岩变形趋于稳定时,拱顶、上测线和下测线基本上同时稳定,Ⅴ级、Ⅳb级以及Ⅳa级围岩施做二次衬砌时距掌子面的距离建议为分别为3倍、2.6倍和2.4倍洞径；②围岩变形与距掌子面距离的关系曲线可分为“台阶”型、“抛物线”型以及“厂”型三种类型。(7)对特大断面板岩隧道围岩变形的影响因素进行了分析,得出影响围岩变形的因素不仅受区域地质构造情况、初始地应力场、围岩自身的性质、地下水和隧道埋深等因素的影响,而且还与隧道断面的形状和尺寸、施工因素等有关。(8)对特大断面板岩隧道围岩变形机理及本构关系进行了研究,得出其变形机制主要表为板、梁的弯曲变形以及结构面张开或闭合,变形本构方程可用层状围岩弯曲变形的本构方程。3.特大断面板岩隧道围岩变形数值分析(1)分析了FLAC3D中关于岩土材料的摩尔-库伦本构模型,以及隧道开挖采用的空单元；并讨论了Burgers模型在FLAC3D中的实现。(2)通过建立三维数值模型,从围岩位移场、应力场和塑性区三个方面对三台阶七步法、弧形导坑预留核心土法和台阶法的围岩空间变形规律进行了分析；并且通过纵向位移场分析,得出了三种工法施工过程中围岩超前变形的规律。(3)分析了围岩蠕变效应和隧道断面尺寸对特大断面板岩隧道围岩变形特征的影响,通过对比分析得出：①蠕变效应在V级围岩隧道开挖后对围岩变形的影响较大,不可忽略,而对Ⅳb级围岩影响较小,在实际研究中可以忽略：②通过对三种典型常用高速铁路断面尺寸的分析,进行数值分析,结果表明：隧道围岩变形存在明显的洞室尺寸效应,断面尺寸一般不会改变围岩原有的变形规律,仅仅是量值上的差异,围岩塑性发展区随断面尺寸的增大而增大,但小断面尺寸能减小隧道围岩扰动区范围。4.特大断面板岩隧道围岩变形预测研究(1)系统分析了支持向量机理论,并对支持向量机核函数和支持向量机模型参数进行了研究。(2)针对支持向量机方法中惩罚因子C和核参数σ的取值问题,将粒子群优化算法引入支持向量机模型中,提出了粒子群优化的支持向量机模型(PSO-SVM),并给出了该模型的建模步骤和方法。(3)分析了支持向量机模型惩罚因子C和核参数σ对时序预测结果影响,验证了粒子群优化算法搜寻模型参数具有快速和准确的特点,避免人为选择支持向量机模型的盲目性。(4)将PSO-SVM模型运用到馒子湾隧道地表沉降和洞内拱顶沉降预测中,并与常规灰色GM(1,1)模型和曲线拟合法预测结果对比分析,结果表明：PSO-SVM模型预测精度最高,且预测能力优于常规灰色GM(1,1)模型和曲线拟合法。5.特大断面板岩隧道围岩变形控制技术研究(1)系统分析了收敛-约束法原理,得出支护施作时机与支护刚度是影响隧道围岩稳定性和支护结构安全性的关键因素。(2)通过对比分析,采用数值分析计算法,研究了Ⅴ级、Ⅳb级和Ⅳa级三种围岩的围岩特征曲线,并根据工程实际,计算出了开挖过程中围岩应力的释放过程。(3)基于收敛-约束法原理,从理论上分析了几种常用支护以及组合支护的支护特征曲线,并提出了初期支护适应性评价的方法。(5)结合馒子湾隧道初期支护参数,计算出初期支护的支护特征曲线,通过分析围岩特征曲线与支护特征曲线的关系,对特大断面板岩隧道初期支护适应性进行评价。(6)通过理论计算对隧道初期支护的安全性进行评价,并绘制了相应的安全系数图,结果表明：型钢+喷锚联合支护具有较好的安全性,满足特大断面板岩隧道施工与运营安全性要求,且V级、Ⅳb级和Ⅳa级支护结构的安全系数均在边墙与仰拱连接处最小,分别为1.24,1.37和1.39,设计与施工过程中应予以注意。(7)采用正交试验法对支护时机与刚度进行优化,选取初期支护与二次衬砌压应力较大,拉应力较小为考察优化指标,提出了V级围岩支护结构的优化组合为初期支护时机为围岩应力释放75%+喷层厚35cm+二次衬砌时机为围岩应力释放96%+二衬厚度为50cm,并通过平面应变数值分析验证了优化组合的合理性。(8)分析了围岩变形控制原则和控制技术体系,从施工工法和支护措施两个方面提出特大断面板岩隧道围岩变形控制技术。论文的创新成果主要包括：(1)运用模糊综合评判方法对Hoek-Brown强度准则的扰动系数D值进行修正,为确定板岩隧道围岩岩体力学参数奠定了理论基础,具有一定的工程参考和应用价值。(2)通过建立三维数值模型,从围岩位移场、应力场和塑性区三个方面对三台阶七步法、弧形导坑预留核心土法和台阶法的围岩空间变形规律进行了分析；并且通过纵向位移场分析,得出了三种工法施工过程中围岩超前变形的规律；基于数值模拟方法,分析了蠕变特性和隧道断面尺寸对围岩变形的影响。(3)采用支持向量机理论(SVM)对板岩隧道变形进行预测,并通过粒子群优化算法(PSO)优化支持向量机参数。通过与传统的预测方法进行对比分析,PSO-SVM预测模型具有一定的合理性和可行性。(4)运用收敛-约束法对特大断面板岩隧道现行的支护体系进行评价,并采用正交试验对特大断面板岩隧道的支护时机与支护刚度进行优化,提出最优化组合。更多还原

【Abstract】 As with the rapid development of China’s transportation construction, super-large cross section tunnels and underground engineering have mushroomed in recent years, especially the passenger dedicated line. In order to overcome the aerodynamic problems caused by the high speed train on passenger dedicated line, super-large-section tunnels are adopted gradually. The clearance area of above ones is larger than100m2, and the excavation area is larger than150m2. Compared with previous tunnels, more strict and new requirements are put forward, mainly contained the mechanical behavior, the cross-section style, lining structure, construction methods, initial support structure mode and support parameters of super-large tunnels etc. The surrounding rock deformation characteristics are influenced by many factors, including geological conditions, design parameters, construction technology and management etc. which are differed with each other. Despite many researchers both at home and abroad, have devoted themselves to the research on the large-cross-section tunnel, there are still some shortcomings both in the theoretical and practical aspects, mainly as follows:(a) The definition of large deformation is not clear, also the cognition is different among the survey and design units and construction teams.(b) The diversity of research leads to the limitation of the research results.(c) It is badly lack of the comprehensive researches by application of systemic test methods. In practical cases, the phenomena that, the area which might occur large deformation has adopted the intensive supporting, whereas it does dot appear large deformation actually, may occur frequently. On the contrary, it may bring construction difficulty in some areas with no predicted large deformation.A large number of scholarly papers demonstrate that, the surrounding rock large deformation problem has become one of the most commonly experienced problems of underground engineering, especially during the constructed period and the control techniques in large-cross-section tunnels. And it is relatively short of relevant references.Relayed on the Shanghai-Kunming Passenger Dedicated Line Chang-Kun Hunan Section Ⅸ tender Manziwan Tunnel, the dissertation is originated in the Natural Science Foundation of Key Projects titled " the rheological deformation control mechanism research of surrounding rock and supporting system in soft slate super-large-section tunnel"(numbered2013CFA110), in Hubei Province. In combination with monographic research titled "the tunnel advance geological prediction and monitoring in Shanghai-Kunming Passenger Dedicated Line Chang-Kun Hunan Section", it carried out in-depth research on deformation characteristics and control measures of super-large-section slate tunnel. The dissertation deeply analyzed the engineering characteristics of slate. Under different construction methods and supporting styles, the mechanical properties and deformation characteristics and failure mechanism have been deeply researched by the application of theoretical analysis, field test (monitoring) and numerical simulation. Also, it emphasized on its influence factors and deformation mechanism. Additionally, the establishment of PSO-SVM model predicted the deformation effectively and was of great significance to the prevention and control. At the same time, the convergence-confinement method was employed to analyze initial supporting structure. To this end, in combination with corresponding theoretical analysis, the surrounding rock characteristic curve and supporting characteristics curves were drawn to evaluate its adaptation and applicability, and optimization supporting structure were put forward. Finally, on the basis of surrounding rock control principles and technical system, it proposed corresponding control measures, which can provide references for the design and construction of similar projects.Specific findings and research are highlighted below:1. Research on slate engineering properties by experiment(1) Through the field geological survey, data collection, and engineering geology report, the general geological situation of the region was elaborated. And the inventory of regional conditions, mainly including topography, strata lithology, geological structure, hydrogeology and geostress, was listed.(2) Through uniaxial and triaxial compression test, mechanical properties of slate under dry state of different structural plane angle were analyzed. It calculated that:(a) The value of slate poisson’s ratio ranged of0.15～0.25, with little relation of angle between structural plane and the loading direction.(b) Under the same confining pressure and different structural plane angle, the slate uniaxial compressive strength and elastic modulus varied from large to small, reducing to a certain value and then gradually increased. (c) Through fitting, it concluded the relationship between uniaxial compressive strength, σ, elastic modulus E, and the intersection angle of structural plane and loading direction.(3) Using the triaxial compression tests, mechanical properties of slate under dry state of different confining pressure were analyzed. It resulted that:(a) Within a certain range, the strain increased by linear along with the stress increasing. While the stress reached to its peak value, the specimen destructed suddenly. Then over the peak value, stress decreased sharply, while the lateral strain increased rapidly.(b) The test demonstrated that, the slate strength was mostly and largely influenced by confining pressure. Further, the compressive strength presented linear increasing tendency with the increasing of confining pressure.(4) Under dry station, the failure characteristics of slate were as follows:(a) Under uniaxial compression condition, shear failure and plane sliding failure mainly occurred.(b) When the dip angle of structural plane was vertical to axial force direction, the specimen mainly occurred shear failure under different confining pressure. Along with the increasing of confining pressure, the intersection angle between fracture surface and the maximum principal stress increased gradually, and the failure surface was more and more smooth.(5) With the confining pressure of lOMPa, mechanical properties of slate were analyzed. It showed that:(a) With the increase of immersion time, the compressive strength and elastic modulus were decreased, while the poisson’s ratio was increased.(b) After soaking, as for the stress-strain curve, before the peak point, it exhibited plastic yield section, while after the peak point, the strain softening occurred. Furthermore, the plastic yield before peak value and the strain softening were more obvious with the increase of bubble water time.(6) Based on fuzzy comprehensive evaluation method, Hoek Brown-strength criterion of disturbance factor was modified, and further to calculate mechanics parameters of slate. Through the comparative analysis of empirical method, Zhang Jianhai modified formula and sound wave test results, the disturbance coefficient value calculated by the proposed method based on fuzzy comprehensive evaluation method, was closed to the value by acoustic test. It indicated that the proposed method was rational. Moreover, it solved the high cost and difficulty in implementation by the acoustic test method, which can be reference for similar engineering applications.(7) Under the drying condition, the hierarchical load method was applied. Axial and lateral transient strain and creep strain occurred per level load. Among which, the instantaneous strain accounted for approximately80%of the whole deformation, and the axial strain was larger than lateral strain deformation, reaching to about2～3times.(8) The axial stress was crucial to creep deformation characteristics. When the axial stress was less than the yield value, the lateral strain and axial strain was linear increased. While when the axial stress was larger than the yield value, the lateral and axial strain changed by exponential relationship. (9) Under different moisture state, with the confining pressure of15MPa, the creep rule was similar to dry states. With the increase of moisture content, the axial and lateral deformation increased in turn.(10) On the basis of summarizing the typical creep model, modified Burgers model was selected to calculate creep parameters, laying foundation for the subsequent numerical analysis.2. Analysis on slate deformation characteristics(1)The tunnel monitoring measurement technology and the method of data processing of Manziwan Tunnel were introduced. Combined with monitoring measurement data, surface settlement and surrounding rock deformation law under different excavation methods were analyzed.(2) The surface transverse settlement obeyed normal distribution, character with large central value. The largest settlement appeared along the tunnel axis, and settlement on two sides decreased with the increasing distance, moreover, surface cumulative settlement decreased along with the increase of tunnel buried depth. When heading face reaching to the monitoring stations, the monitoring position was uplift or subsidence possibly. While the heading face crossing the monitoring position, due to the action of supporting ring closure, the surface settlement located in the distance of1to2times diameters, began to convergence.(3) Through the surrounding rock deformation-time characteristic curve, the deformation laws under different excavation methods along with the time were analyzed.(4) Via comparative analysis of fitting formula, exponential function was the best one for deformation characteristics. Further, the function, y=a(1-e-bt), was applied to crown settlement and upper bench convergence analysis, while for they=ae-b/t, it was more precious in lower bench convergence analysis.(5) As for radial release rate of deformation under three kinds of method, during an identical period, the crown was the smallest, and the largest one was the lower measured line. Furthermore, the release rate of each section reached to100percent after30days of its excavation.(6) Relayed on monitoring measurement data in Manziwan Tunnel and different class of surrounding rock, the relationship between the deformation and the distance from heading face were analyzed. It resulted that:(a) When deformation was stability, the vault, upper measured line and lower measured line were basically stable at the same time. And it recommended, as for the secondary lining opportunity, the distance to heading face was3D,2.6D and2AD (where D was the excavation diameter), for V, IVb and IVa level surrounding rock respectively.(b) The relationships between deformation and the distance to heading face were divided into three types,"steps" type,"parabola" shape and "factory" type.(7) The influence factors of surrounding rock deformation were analyzed. It indicated that it influenced by regional geological tectonic situation, the initial ground stress field, the nature property, ground water and tunnel buried depth, as well as the tunnel section shape and size and construction and so on.(8) The surrounding rock deformation mechanism and constitutive relation were studied. It demonstrated the bending deformation of plate and beam and opening and closed of structural plane were performed as deformation mechanism. As for constitutive relation, the layered constitutive equation was selected.3. Research on numerical simulation during construction period(1) It analyzed Mohr-Coulomb constitutive model of geotechnical material in FLAC, and the null element. Also it discussed the implementation of Burgers model in FLAC3D.(2) Through the establishment of three-dimensional numerical model, and with the emphasis on the displacement field, stress field and plastic zone of surrounding rock, spatial deformation law of surrounding rock are analyzed by different construction methods. Further, through the longitudinal displacement field analysis, it obtained the advanced deformation characteristics.(3) It deeply analyzed the creep effect and tunnel section size effect, through comparing analysis, it resulted that:(a) As for V level surrounding rock, creep effect played an obvious role on its deformation after excavation, and it should not be neglected. Whereas, in terms of IV level one, it can be neglected in practical case due to its tinny effects.(b) Based on numerical simulation on three typical commonly used high speed railway section size, it proved that, as for the surrounding rock deformation, size effect was obvious. Generically, deformation law would not change, while only the difference in its value. And the plastic area developed with the increasing of section size, but small section size can reduce the excavation disturbance area.4. Research on deformation prediction(l)The system principle of support vector machine (SVM) theory was analyzed, as well as the kernel function of support vector machine (SVM) and support vector machine (SVM) model parameters were elaborated presented.(2)In view of the value of penalty factor C and nuclear parameter σ, the particle swarm optimization algorithm was introduced to the SVM model, and the support vector machine (SVM) model of particle swarm optimization (PSO-SVM) was put forward. An inventory of the modeling steps and methods were listed accordingly.(3) With an emphasis analysis on the time-series forecasting results affected by penalty factor C and nuclear parameter σ, it verified the particle swarm optimization algorithm for model parameter was practical, rapid and accurate, and avoided subjectivity and blindness by human.(4) By the application of PSO-SVM model, it conducted deformation prediction of surface subsidence and crown settlement in Manziwan Tunnel. Through comparative analysis with conventional grey GM (1,1) model and curve fitting prediction results, it resulted; the PSO-SVM model was with highest prediction accuracy, and with superior prediction ability than other two methods.5. Research on surrounding rock deformation control technology(1) Through a systematical analysis on the convergence-confinement principle, it obtained the supporting opportunity and stiffness was of great importance on the surrounding rock stability of and supporting structure safety.(2) By the application of numerical simulation, the surrounding rock characteristic curves, including the V, IVa and IVb level, were drawn. As according to the in-suit condition, the stress releasing process during excavation period was carried out.(3) On the basis of convergence-confinement method, the most commonly used bolting and combined bolting support characteristic curves were obtained theoretically, as well as the primary support adaptability evaluation method was put forward.(4) In combination with primary support parameters in Manziwan Tunnel, its primary support characteristic curve was drawn. The primary support adaptability evaluation was conducted through the relationship between surrounding rock characteristic curve of and supporting characteristics curves.(5) The evaluation on primary support safety was operated through theoretical calculation and corresponding safety coefficient figures were drawn. It indicated that the steel and spray net support exhibited better safety performance and meet the security requirements in construction and operation in large-cross-section slate tunnel. Furthermore, the minimum safety coefficient of V, IVb and IVa level werel.24,1.37and1.39respectively, which appeared in the connected section of sidewall and inverted arch joint. Thus, much attention should be paid on the design and construction process.(6) Based on orthogonal design for the optimization of supporting opportunity and stiffness, a reasonable optimal indictor was selected and the combination was calculated. As for the V level surrounding rock, it showed that the optimize combination was:with75percent of stress releasing for supporting opportunity+35cm of spray thickness for primary support opportunity, and with96percent of stress releasing for supporting opportunity+50cm of spray thickness for secondary support, and the plane strain numerical simulation was performed as a basis for the validate results and its rationality.(7) The deformation control principle of and technology system were elaborated analysis, and in the view of construction methods and supporting measures, surrounding rock deformation control technology for large-cross-section slate tunnel were proposed.The innovations of the dissertation were as following:(1) The fuzzy comprehensive evaluation method was adopted to modify the Hoek Brown’s strength criterion of disturbance factor D value. It laid a theoretical foundation for ascertaining surrounding rock mechanics parameters, and possessed practical reference and application.(2) Through the three-dimensional numerical calculation results, mainly from three aspects of displacement field, stress field and plastic zone, spatial deformation law was analyzed under different construction methods. In special, with an emphasis on longitudinal displacement field analysis, the advance deformations under different construction methods were obtained. Also, deformation characteristics affected by creep property and size effect were analyzed by numerical simulation.(3) The support vector machine (SVM) was applied to predict surrounding rock deformation and the particle swarm optimization algorithm (PSO) was adopted to optimize the support vector machine (SVM) parameters. By comparative analysis with traditional prediction methods, PSO-SVM prediction model exhibited a rational and feasible performance.(4) The application of convergence-confinement method was conducted to evaluate the adopted supporting system. Additionally, optimization combination was put forward by orthogonal design for optimization of supporting opportunity and stiffness.更多还原