【作者】 景锋；

【导师】 盛谦；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2009， 博士

【摘要】 地应力是赋存于岩体中的自然应力,其不仅是地质环境与地壳稳定性评价,也是地质工程设计和施工的重要资料之一。随着我国交通、水利水电、核废料存储、石油和矿山等行业的发展,人类在地壳上活动空间的广度和深度不断发展,地应力对工程和科研的影响和作用日益显著。现我国已积累了大量的地应力实测数据和工程实例,为研究我国大陆浅层地壳地应力场分布规律及工程扰动特征,本文基于我国大陆及邻区的地质架构、震源机制解和大地形变场等特征,分析了我国大陆及邻区现代构造应力场特征,通过收集大量的地应力实测资料,系统研究了我国大陆地区浅层地壳实测地应力的分布规律,另以三峡永久船闸和大岗山地下厂房为工程背景,通过开挖全过程数值仿真,研究了深挖岩坡和大型地下洞室开挖地应力场的工程扰动特征,主要研究工作和成果体现在以下几个方面:（1）总结分析了各种地应力测定方法的优缺点和适用性,从岩体的非均匀性、测定方法本身以及地质力学的角度,研究了不同方法间测定结果的差异,形成对地应力测定方法及其结果的科学评价体系。（2）针对原生裂隙重张试验确定裂隙法向应力精度高,并可进行大尺度三维地应力测量,但当原生裂隙间距大时,应考虑应力梯度的问题。研究了考虑应力梯度的原生裂隙水压致裂法三维地应力测量,基于地应力沿埋深的分布规律,简化出单孔的线性应力梯度形式及区域应力场的全应力张量表述,推导了基于遗传算法和最小二乘法的计算过程,并首次在国内工程中得到了运用。（3）通过总结中国大陆及邻区地壳的形成演化、岩石圈结构、断裂体系分布和板块活动等特征,分析了我国大陆及邻区的现代地质架构特征。并根据我国大陆及邻区的震源机制解和大地形变的已有研究成果,系统分析了我国大陆及邻区的现代构造应力场特征和动力学特性。（4）通过收集大量的地应力实测数据和相关资料,分析了我国大陆地区实测地应力的应力方向分布规律。根据我国400多个钻孔的实测地应力数据建立了数据库,筛选了受地形地貌和局部地质条件影响小的约450组数据作为统计样本,研究了我国大陆浅层地壳实测地应力沿埋深的分布规律。建立了我国大陆地区垂直应力σ_v、最大水平主应力σ_H和最小水平主应力σ_h随埋深的散点分布图,建立了（σ_H+σ_h）/2σ_v、σ_H/σ_h、σ_H/σ_v、σ_h/σ_v随埋深分布的散点图,并进行了相应的统计分析,系统研究了我国大陆地区实测地应力沿埋深的分布规律。（5）基于所建立的地应力实测数据库,按地质成因分类,岩浆岩选取了111组数据,沉积岩选取了232组,变质岩选取了70组,建立了岩浆岩、沉积岩和变质岩地应力沿埋深的各种散点分布图,研究了不同岩性的地应力分布规律,及岩性变化对地应力的影响。筛选带有弹性模量的地应力的实测数据,研究了弹性模量随埋深的变化规律,并研究了弹性模量与应力量值的关系,以及对σ_H、σ_h和σ_v的影响。（6）研究了现今地应力的组成,结合地应力沿埋深的分布及孔隙水、温度、地表地质作用等对地应力的影响规律,在侧向约束应力状态的基础上,探讨了考虑多因素的地应力估算模型。（7）以三峡水利枢纽和大岗山水电工程为实例,利用震源机制解、水系形态分布、断层擦痕等分析了工程区域地应力场,基于工程区及邻区实测地应力结果,并结合工程区地应力场反演,研究了大型工程区的地应力场分布特征、影响因素。并从地质力学的角度,研究了区域与工程区地应力场的联系与差异。（8）以三峡永久船闸高边坡和大岗山地下厂房工为工程背景,对深挖岩质高边坡和大型地下洞室开挖周边岩体的应力场、变形场和塑性破坏区的分布特征和变化规律,进行了全过程数值仿真研究。根据工程开挖后的应力场扰动特征,提出了将应力场分为应力强扰动区、应力弱扰动区和应力未扰动区三个区。探讨了根据周边岩体的I₁、J₂、Lode参数、应力量值的变化规律,进行地应力场工程扰动分区,并分析了其工程意义。更多还原

【Abstract】 Geostress is natural stress which hosted in the rock mass.It is one of most important data for the design and construction of the geological engineering,the evaluation index of geological environment and crustal stability.With the fast developing of transportation,water resources and hydropower,nuclear waste disposal, petroleum,mining and etc,in our country,the width and depth of human activity space is being more and more widely,and geostress is being more and more important for engineering and research.There are much geostress measured data and engineering examples in our country.In order to research the distribution rules of geostress field and the disturbed characteristics of construction in our country’s mainland,based on the geological frame of our country and neighboring region,the mechanism solutions of earthquake focus and the characteristic of the geodetic deformation fields evolution,the characteristic of the tectonic stress field in our country was studied.By collecting vast geostress measured data,the distribution rules of measured geostress in our country was systematically studied.Based on the background of Three Gorges permanent lock slope and Dagangshan underground powerhouse,the characteristics of geostress field and disturb zones for high slope and large underground cavern were studied using the whole process numerical simulation. The main research work and achievement of this dissertation are as follows.（1） the advantages and disadvantages and the applicability of various geostress measured methods were summarized.From the view of the rock mass nonuniformity, measured method itself and geomechanics,the result difference among different measured methods were studied,which formed the scientific evaluation system of geostress measured methods and its results.（2） The preexisting fracture reopening test can determine fracture normal stress with high precision,and also can measure large scale three dimensional geostress.But if the space of the preexisting fracture was large,the stress gradient should be considered.Considering the stress gradient,the preexisting fracture hydraulic fracturing three dimensional geostress measured test was studied.Base on the distribution rule of the geostress with depth,the complete stress tensor expression of the linear stress gradient form of the vertical hole and the regional tectonic stress field were simplified,and the calculation process based on the genetic algorithm and the least square method were derived.It was first applied in the projects in our country. （3） From summarizing the characteristics of the formation and evolution of earths crust,the lithosphere structure,the distribution of fault systems and the plate activity in Chinese mainland and neighboring region,the nowadays characteristic of the geological condition in these regions were analyzed.Based on the existing research results of mechanism solutions of earthquake focus and geodetic deformation in Chinese mainland and neighboring region,the characteristic of nowadays tectonic stress field and the dynamics property in these regions were systemic studied.（4） Through collecting a vast amount of the measured geostress data and correlative materials,the distribution property of the measured stress orientation in Chinese mainland was analyzed.Through collecting the measured geostress data from about 400 drillings,a database was established.450 groups data with less topographical and local influence are selected as statistical samples,to study the distribution rule of the shallow crustal geostress in Chinese mainland.The dispersed point charts of the vertical stress,the maximum and the minimum horizontal principal stress varying with the depth were established.And the dispersed point charts of the ratios of the average horizontal principal stress and the vertical stress,the maximum and the minimum horizontal principal stress,the maximum and the minimum horizontal principal stress,the maximum horizontal principal stress and the vertical stress,the minimum horizontal principal stress and the vertical stress were also established.After corresponding statistical analysis,the distribution rules of the geostress in Chinese mainland were systemic studied.（5） According to their geological origins,111 groups of magmatic rocks data, 232 groups of sedimentary rocks data and 70 groups of metamorphic rocks data were selected from the established database of measured geostress data.The dispersed point charts of the geostress in the three types of rock varying with the depth were established,and the distribution rules of the geostress in different lithology were studied.Based on the measured geostress data with elastic modulus,the change rule of elastic modulus with depth was studied.The relationship between the rock strength, elastic modulus and the magnitude of geostress,and its impact on the maximum,the minimum horizontal principal stress and the vertical stress were studied.（6） The component of nowadays geostress were studied.According to the distribution rules of the geostress of depth and the influence rules of geostress by the pore water,temperature,geologic effect,the multi-factor geostress model with lateral restraint were discussed.（7） Referring to the Three Gorges Project and Dagangshan hydropower project as examples,the stress field of engineering areas was analyzed with mechanism solutions of earthquake focus,water system form distribution and fault striation. Based on the measured geostress in engineering areas and neighboring region, combining with the stress field back analysis of engineering areas,the distribution characteristics and the influencing factors of stress field of the big engineering areas were studied.From the geomechanics point of view,the relationship and difference between the regional tectonic and engineering areas stress field were analyzed.（8） Based on the background of Three Gorges permanent lock slope and Dagangshan underground powerhouse,using the whole process numerical simulation, the distribution characteristics and variation law of the stress field,deformation field and plastic zones of rock mass surrounding the large-scale underground cavern and the deep excavation and high rock slope were system studied.Based on the disturbed characteristics of the stress field after excavation,the stress field were divided into three zones,strong stress disturbed zones,weak stress disturbed zones and none stress disturbed zones.The change law of I₁,J₂,Lode parameters and the magnitude of the geostress of the surrounding rock were analyzed, and the methods for distinguish the disturbed zones and its engineering sense were also analyzed.更多还原