Effects of fracture lineaments and in-situ rock stresses on groundwater flow in hard rocks: a case study from Sunnfjord, western Norway

Systematic field mapping of fracture lineaments observed on aerial photographs shows that almost all of these structures are positively correlated with zones of high macroscopic and mesoscopic fracture frequencies compared with the surroundings. The lineaments are subdivided into zones with different characteristics: (1) a central zone with fault rocks, high fracture frequency and connectivity but commonly with mineral sealed fractures, and (2) a damage zone divided into a proximal zone with a high fracture frequency of lineament parallel, non-mineralized and interconnected fractures, grading into a distal zone with lower fracture frequencies and which is transitional to the surrounding areas with general background fracturing. To examine the possible relations between lineament architecture and in-situ rock stress on groundwater flow, the geological fieldwork was followed up by in-situ stress measurements and test boreholes at selected sites. Geophysical well logging added valuable information about fracture distribution and fracture flow at depths. Based on the studies of in-situ stresses as well as the lineaments and associated fracture systems presented above, two working hypotheses for groundwater flow were formulated: (i) In areas with a general background fracturing and in the distal zone of lineaments, groundwater flow will mainly occur along fractures parallel with the largest in-situ rock stress, unless fractures are critically loaded or reactivated as shear fractures at angles around 30° to σ_H; (ii) In the influence area of lineaments, the largest potential for groundwater abstraction is in the proximal zone, where there is a high fracture frequency and connectivity with negligible fracture fillings. The testing of the two hypotheses does not give a clear and unequivocal answer in support of the two assumptions about groundwater flow in the study area. But most of the observed data are in agreement with the predictions from the models, and can be explained by the action of the present stress field on pre-existing fractures.     

基于分布式光纤温度示踪探测裂隙岩体地下水渗流特征

认识深部裂隙岩体中的地下水渗流特征(流速、渗流路径等),是深部地质工程开发建设的重要前提。近年来,分布式光纤测温技术作为识别深部裂隙岩体地下水渗流特征的有效方法,在国外开展了大量的研究,但在国内鲜少见在实际场地开展的相关工作。本研究以我国首个地下实验室场址甘肃北山新场花岗岩岩体中的两个钻孔(BSQ02及BSQ03)为试验对象,开展基于分布式光纤测温(Fiber-Optic Distributed Temperature Sensing, FO-DTS)的现场温度-水力试验,实现了对钻孔地下水温度的高精度、连续性观测。通过分析现场试验获取的钻孔温度-深度剖面随时间的变化,推断BSQ02在试验过程中存在外源地下水的流入,然后结合钻孔柱状图对钻孔中的入流导水裂隙进行了定位;基于现场观测数据建立了钻孔的渗流-传热耦合数值模型,反演估算出钻孔中地下水平均流速为0.01 m·s^-1,通过裂隙流入地下水温度小于钻孔中原地下水温度,两者之间的温度差为0.7℃,通过裂隙流入的地下水流速为1×10^-5 m·s^-1,获取了地下水的渗流特征。该...     

Numerical investigation of groundwater outbursts near faults in underground coal mines

Permeable geologic faults in the coal seam can cause intermittent production problems or unexpected amounts of groundwater outburst from the underlying aquifers. With the acknowledgment of the basic mechanism for groundwater outbursts, the groundwater outburst along the fault zones in coal mines are numerically investigated using RFPA, a numerical code based on FEM. The fracture initiation, propagation, and coalescence in the stressed strata and the seepage field evolution in the stress field are represented visually during the whole process of groundwater outburst. The numerically obtained damage evolution shows that the floor strata could be classified as three zones, i.e. mining induced fracture zone, intact zone and fault reactivation zone, in which the intact zone is the key part for resisting groundwater outburst and directly determines the effective thickness of water-resisting rock layer. With understanding of the evolution of stress field and seepage flow in floor strata, the groundwater outburst pathway is calibrated and the transformation of floor rock mass from water-resisting strata to outburst pathway is clearly illuminated. Moreover, it is shown that geometrical configuration, including inclination angle of faults and seam drop along faults, have an important influence on groundwater outburst. Finally, based on geological, hydrogeology survey and numerical results, the mechanism analysis of groundwater outburst in an engineering case is studied, which can provide significantly meaningful guides for the investigation on mechanism and prevention of groundwater outburst induced by faults in practice.     

Polyaxial stress-dependent permeability of a three-dimensional fractured rock layer

A study about the influence of polyaxial (true-triaxial) stresses on the permeability of a three-dimensional (3D) fractured rock layer is presented. The 3D fracture system is constructed by extruding a two-dimensional (2D) outcrop pattern of a limestone bed that exhibits a ladder structure consisting of a “through-going” joint set abutted by later-stage short fractures. Geomechanical behaviour of the 3D fractured rock in response to in-situ stresses is modelled by the finite-discrete element method, which can capture the deformation of matrix blocks, variation of stress fields, reactivation of pre-existing rough fractures and propagation of new cracks. A series of numerical simulations is designed to load the fractured rock using various polyaxial in-situ stresses and the stress-dependent flow properties are further calculated. The fractured layer tends to exhibit stronger flow localisation and higher equivalent permeability as the far-field stress ratio is increased and the stress field is rotated such that fractures are preferentially oriented for shearing. The shear dilation of pre-existing fractures has dominant effects on flow localisation in the system, while the propagation of new fractures has minor impacts. The role of the overburden stress suggests that the conventional 2D analysis that neglects the effect of the out-of-plane stress (perpendicular to the bedding interface) may provide indicative approximations but not fully capture the polyaxial stress-dependent fracture network behaviour. The results of this study have important implications for understanding the heterogeneous flow of geological fluids (e.g. groundwater, petroleum) in subsurface and upscaling permeability for large-scale assessments.     

构造应力对裂缝形成与流体流动的影响

裂缝是低渗透储层流体流动的主要通道,控制了低渗透油气藏的渗流系统。低渗透储层裂缝的形成与流体密切相关,高流体压力引起岩石内部的有效正应力下降,导致岩石剪切破裂强度下降,使岩石容易产生裂缝。高孔隙流体压力还造成某一点的应力摩尔圆向左移动,可以使其最小主应力(σ3)由压应力状态变成拉张应力状态,从而在岩石中形成拉张裂缝。裂缝的渗透性受现今应力场的影响,通常与现今应力场最大主压应力近平行分布的裂缝呈拉张状态,连通性好,开度大,渗透率高,是主渗透裂缝方向。构造应力对沉积盆地流体流动的影响主要表现在三个方面:(1)构造应力导致的岩石变形,不仅提供了流体流动的通道,而且还改变了岩石的渗透性能;(2)在构造强烈活动时期,构造应力的快速变化是流体流动的重要驱动力;(3)岩石中应力状态影响多孔介质的有效应力,从而影响介质中的渗流场。当作用在含流体介质上的构造应力发生改变时,岩石孔隙体积变小,构造应力首先由岩石的骨架来承担;当岩石孔隙体积减小到一定程度时,构造应力由孔隙流体来承担,从而影响岩层渗流场的变化。     

Long-term stability of flow-path structure in crystalline rocks distributed in an orogenic belt, Japan

Most evaluations of the contaminant retardation processes likely to be important in geological disposal (e.g. for high level radioactive waste (HLW)) consider only the present characteristics of fractures and associated mineral infills. Relatively little attention has been given to possible long-term changes in these features, and their influence on groundwater flow. The work reported here seeks to provide analogous evidence that such changes are not likely to be important and hence to improve confidence in the presently adopted evaluation methodology and its long-term applicability.

In the orogenic belt that is formed by the Japanese islands, there are wide areas of crystalline rock. The rocks in each area have a distinctive age sequence which is partly reflected in the characteristics of the fracture systems and associated mineral fillings that occur. These characteristics generally imply that groundwater and solutes can be conducted through fracture networks, except in the cases of fault zones or crushed zones. The structural and mineralogical features of these networks readily illustrate how certain contaminants might react and be retarded by the fracture fillings and open pore geometry, due to chemical sorption and/or physical retardation.

Here, we describe the fracture systems developed in crystalline rocks with different ages that are intruded into the Japanese orogenic belt. The aim is to build a model for the long-term fracturing process and hence to evaluate fracture ‘stability’. In particular, the comparisons are made between the fracture geometries and the frequencies observed in the 1.9–0.8 Ma Takidani Granodiorite (the youngest exposed pluton in the world), the ca. 67 Ma Toki Granite and the ca. 117 Ma Kurihashi Granodiorite located in central to northwest Japan. The observations show that all these crystalline rocks have similar fracture frequencies, with 1 to 2 fractures per meter in the massive part of rock bodies. Mineralogical studies and dating analyses of fracture fillings also suggest that fractures are relatively physically stable. Major new fractures tend not to be created in the massive part of rock bodies even when a pluton has been subjected to the regional stresses of plate movements with a duration of about 100 Ma. The results show the unique characteristics of the fracture forming process and the relatively stable geometries of fracture network systems in crystalline rocks distributed within the orogenic belt. This analogue also enables us to provide a model to build confidence in a technical approach applicable for modeling of hydrogeology and geology over long time scales under the orogenic stress field present in Japan. The model may also be useful for other stable tectonic settings as well as for a characterizing sites in crystalline rocks for the possible geological disposal of HLW and other toxic wastes.     

Application of Stochastic Fracture Network with Numerical Fluid Flow Simulations to Groundwater Flow Modeling in Fractured Rocks

ＩＮＴＲＯＤＵＣＴＩＯＮＧｒｏｕｎｄｗａｔｅｒｏｒｆｌｕｉｄｆｌｏｗｍｏｄｅｌｉｎｇｉｎｆｒａｃｔｕｒｅｄｒｏｃｋｓｉｓａｃｏｍｐｌｉｃａｔｅｄｔｈｅｏｒｅｔｉｃａｌａｎｄａｐｐｌｉｅｄｔｏｐｉｃ.Ｂｏｔｈｔｈｅｏｒｅｔｉｃａｌｌｙａｎｄｏｐｅｒａｔｉｏｎａｌｌｙ ,ｉｔｉｓｉｍｐｏｒｔａｎｔｉｎｍａｎｙｆｉｅｌｄｓｓｕｃｈａｓｇｅｏｌｏｇｉｃａｌａｎｄｈｙｄｒｏｇｅｏｌｏｇｉｃａｌｅｎｇｉｎｅｅｒｉｎｇ ,ｅｎｖｉｒｏｎｍｅｎｔａｌｅｎｇｉｎｅｅｒｉｎｇａｎｄｐｅｔｒｏｌｅｕｍｅｎｇｉｎｅｅｒｉｎ…     

Influence of Heterogeneity of Mechanical Properties on Hydraulic Fracturing in Permeable Rocks

Summary Numerical simulations of circular holes under internal hydraulic pressure are carried out to investigate the hydraulic fracture initiation, propagation and breakdown behavior in rocks. The hydraulic pressure increases at a constant rate. The heterogeneity of the rocks is taken into account in the study by varying the homogeneity index. In addition, the permeability is varied with the states of stress and fracture. The simulations are conducted by using a finite element code, F-RFPA^2D, which couples the flow, stress and damage analyses. The simulation results suggest that the fracture initiation and propagation, the roughness of the fracture path and the breakdown pressure are influenced considerably by the heterogeneity of rocks. The hole diameter elongation and the stress field evolution around the fracture tip during the fracture propagation can also provide useful information for the interpretation of the hydraulic fracturing behaviour.     

Hydrogeologic control of shear-related fracturing in Blue Ridge basement rocks: a case study from production wells in the Marshall Metagranite,Fauquier County,Virginia (USA)

Borehole geophysical logging of four production wells completed in Precambrian metagranite in Fauquier County, Virginia (USA), was conducted to characterize stratigraphy, collect water-bearing fracture orientations and describe vertical hydraulic gradients in the vicinity of each borehole. Long-term (48–90 h) single-well pump test data were reevaluated for each well to better characterize this locally important aquifer system. Single-well aquifer test analyses indicate mid-to-late-time infinite acting radial flow conditions within the fractured rock aquifer, followed by increasing late-time contribution of stored groundwater from recharge boundaries. Later-time pump test results are believed to indicate that water-bearing fractures within the metagranite are ultimately recharged by groundwater stored within the regolith. Assumptions about the presence of a recharge boundary sourced by the regolith were tested with a simple groundwater flow model that was calibrated to observed drawdown data associated with one of the long-term pump tests. This study identifies fracturing associated with shear-related metamorphic fabrics in the wellbore and demonstrates the significance of these fractures as mechanisms for accessing groundwater. Results from this investigation indicate that shear-related metamorphic fabrics can be important structures for integrating transmissive fracture networks within the Marshall Metagranite and possibly within other Blue Ridge basement rocks possessing similar metamorphic history.

     

Erratum: Properties of a pair of fracture networks produced by triaxial deformation experiments: insights on fluid flow using discrete fracture network models

Results of a series of deformation experiments conducted on gabbro samples and numerical models for computation of flow are presented. Rocks were subjected to triaxial tests (σ1 > σ2 = σ3) under σ3 = 150 MPa confining pressure at room temperature, to generate fracture network patterns. These patterns were either produced by keeping a constant confining pressure and loading the sample up to failure (conventional test: CT), or by building up a high differential stress and suddenly releasing the confining pressure (confining pressure release test: CPR). The networks are similar in overall density but differ primarily in the orientation of smaller fractures. In the case of CT tests, a conjugate fracture set is observed with one dominant fracture zone running at about 20° from σ1. CPR tests do not show such a conjugate pattern and the mean fracture orientation is at around 35° from σ1. Discrete fracture network (DFN) methodology was used to determine the distribution of flow and hydraulic head for both fracture sets under simple boundary conditions and uniform transmissivity values. The fracture network generated by CT and CPR tests exhibit different patterns of flow field and hydraulic head configurations, but convey approximately the same amount of flow at all scales for which DFN models were simulated. The numerical modelling results help to develop understanding of qualitative differences in flow distribution that may arise in rocks of the same mineralogical composition and mechanical properties, but under the influence of different stress conditions, albeit at similar overall stress magnitude.

     

A field study (Massachusetts, USA) of the factors controlling the depth of groundwater flow systems in crystalline fractured-rock terrain

Groundwater movement and availability in crystalline and metamorphosed rocks is dominated by the secondary porosity generated through fracturing. The distributions of fractures and fracture zones determine permeable pathways and the productivity of these rocks. Controls on how these distributions vary with depth in the shallow subsurface (<300 m) and their resulting influence on groundwater flow is not well understood. The results of a subsurface study in the Nashoba and Avalon terranes of eastern Massachusetts (USA), which is a region experiencing expanded use of the fractured bedrock as a potable-supply aquifer, are presented. The study logged the distribution of fractures in 17 boreholes, identified flowing fractures, and hydraulically characterized the rock mass intersecting the boreholes. Of all fractures encountered, 2.5% are hydraulically active. Boreholes show decreasing fracture frequency up to 300 m depth, with hydraulically active fractures showing a similar trend; this restricts topographically driven flow. Borehole temperature profiles corroborate this, with minimal hydrologically altered flow observed in the profiles below 100 m. Results from this study suggest that active flow systems in these geologic settings are shallow and that fracture permeability outside of the influence of large-scale structures will follow a decreasing trend with depth.     

The influence of Cenozoic tectonics on the groundwater-production capacity of fractured zones: a case study in Sao Paulo, Brazil

A new procedure is developed to correlate structural lineaments recognised through air-photo interpretation with subsurface fracture features that are associated with zones of high groundwater production in fractured-rock environments. The analysis approach is referred to as the homogeneous tectonic domain (HTD) method and involves correlating the lineament features of a given area with the orientation of the primary stress fields and fracture structures associated with the recent tectonic history that affected the region of study. The main premise of the method is that the most recent tectonic events in a given area have had the most significant influence on the nature of the existing fracture network and subsequently on the regional groundwater flow characteristics. A study site was selected within the state of S?o Paulo, Brazil, where a complex tectonic history dating back to Precambrian time has generated significant fracture porosity in the bedrock environment. The bedrock is heavily used in this area as a domestic and industrial aquifer. The most recent tectonic activity is associated with five distinct Cenozoic events that generated fracture features through both shear and extension stress fields. Due to the mode of formation, fracture zones generated by extension tend to have the largest effective apertures and are the most conductive to groundwater. By applying the HTD method in a series of test areas where specific Cenozoic events were dominant, fracture trends generated by shear and extension mechanisms could be identified. Water-well production capacity was correlated with proximity to extension-type structures in most cases. Other factors, such as the type of rock the well was completed in, had a much weaker influence on well capacity. Through this application, the HTD approach is shown to provide a methodology for delineating fractured areas within rock environments that have high potential for groundwater-resource development by combining classical lineament analysis with a clear understanding of the tectonic history of a given area. Electronic Publication     

Hydrochemical characteristics and evaluation of the granite aquifer in the Alwadeen area,southwest Saudi Arabia

This study was carried out in the Alwadeen area of Khamis Mushayt district of southwestern Saudi Arabia to evaluate the hydrochemical characteristics of the shallow hard rock aquifers. These hard rock aquifers mostly comprise granites and contain significant quantities of groundwater that complement the available groundwater from the unconsolidated alluvial sediments in the nearby wadis. The field investigation indicates two main fracture sets which intersect each other and are oriented in the west-northwest and east-west directions. The granitic rocks in the area are intruded by coarse-grained and quartz-rich monzogranite and pegmatite veins. Hydrogeologically, the fracture systems are important since they facilitate the groundwater storage and assume the transmissive function during times of groundwater abstraction. Given the fact that groundwater in the fractured rock aquifers generally occurs at shallow depths, it may be exposed to contamination from surface and/or near-surface sources, and it is therefore important to evaluate its quality. To this end, a hydrochemical analysis was carried out on six groundwater samples collected from the area. The hydrochemistry revealed that the groundwater is fairly fresh, and facies analysis reveals mixed Na-Cl and Ca-Mg-Cl-SO₄ types. Overall, the results reveal that the groundwater is saturated with calcite and dolomite, but unsaturated with gypsum and halite. The degree of salinity increases in the direction of the groundwater flow due to increased rock-water interaction.     

The hydrogeology of the Ballimore region,central New South Wales,Australia: an integrated study

The integrated use of geophysical, geological, hydrogeochemical and hydrogeological data has allowed the development of a plausible conceptual model for groundwater flow in the Ballimore region. A realistic model for this under-explored system could not be derived solely by the use of hydrogeological data. Interpretation of the available datasets indicates that two groundwater systems are active: a regional and a local system. These are separated by a regionally extensive aquiclude. Groundwater flow in the regional groundwater system is controlled by the structural fabric of the Palaeozoic basement rocks. The local groundwater system is restricted to the Permian to Recent sequence of cover rocks. The local groundwater system is subdivided into three cells: the deep, intermediate and shallow cells. Groundwater flow within the deep cell of the local groundwater system is controlled by fracture flow. Groundwaters from this aquifer are under artesian pressure and are effervescent (CO₂-gas). The intermediate cell is a leaky aquitard that acts as a mixing zone between the deep and shallow cells. Groundwater flow within the shallow cell is controlled by the influx of surface waters which migrate laterally through permeable beds.     

Numerical modelling of fluid flow tests in a rock fracture with a special algorithm for contact areas

The fluid flow in rock fractures during shear processes has been an important issue in rock mechanics and is investigated in this paper using finite element method (FEM), considering evolutions of aperture and transmissivity with shear displacement histories under different normal stress and normal stiffness conditions as measured during laboratory coupled shear-flow tests. The distributions of fracture aperture and its evolution during shearing were calculated from the initial aperture, based on the laser-scanned sample surface roughness results, and shear dilations measured in the laboratory tests. Three normal loading conditions were adopted in the tests: simple normal stress and mixed normal stress and normal stiffness to reflect more realistic in situ conditions. A special algorithm for treatment of the contact areas as zero-aperture elements was used to produce more accurate flow field simulations, which is important for continued simulations of particle transport but often not properly treated in literature. The simulation results agree well with the measured hydraulic apertures and flow rate data obtained from the laboratory tests, showing that complex histories of fracture aperture and tortuous flow fields with changing normal loading conditions and increasing shear displacements. With the new algorithm for contact areas, the tortuous flow fields and channeling effects under normal stress/stiffness conditions during shearing were more realistically captured, which is not possible if traditional techniques by assuming very small aperture values for the contact areas were used. These findings have an important impact on the interpretation of the results of coupled hydro-mechanical experiments of rock fractures, and on more realistic simulations of particle transport processes in fractured rocks.     

地壳岩石半脆性非均匀蠕变破坏-失稳的判别

本文通过分析地壳半脆性域岩石蠕变破坏-失稳的复杂性,提出应该建立能够判别地壳岩石半脆性蠕变破坏-失稳基本规律的准则,以便尽可能准确地预测地壳半脆性域岩石蠕变破坏-失稳的类型及其与温度压力等环境条件的关系。     

Investigating the role of hydromechanical coupling on flow and transport in shallow fractured-rock aquifers

Fractured-rock aquifers display spatially and temporally variable hydraulic conductivity generally attributed to variable fracture intensity and connectivity. Empirical evidence suggests fracture aperture and hydraulic conductivity are sensitive to in situ stress. This study investigates the sensitivity of fractured-rock hydraulic conductivity, groundwater flow paths, and advection-dominated transport to variable shear and normal fracture stiffness magnitudes for a range of deviatoric stress states. Fracture aperture and hydraulic conductivity are solved for analytically using empirical hydromechanical coupling equations; groundwater flow paths and ages are then solved for numerically using groundwater flow and advection-dispersion equations in a traditional Toth basin. Results suggest hydraulic conductivity alteration is dominated by fracture normal closure, resulting in decreasing hydraulic conductivity and increasing groundwater age with depth, and decreased depth of long flow paths with decreasing normal stiffness. Shear dilation has minimal effect on hydraulic conductivity alteration for stress states investigated here. Results are interpreted to suggest that fracture normal stiffness influences hydraulic conductivity of hydraulically active fractures and, thus, affects flow and transport in shallow (<1 km) fractured-rock aquifers. It is suggested that observed depth-dependent hydraulic conductivity trends in fractured-rock aquifers throughout the world may be partly a manifestation of hydromechanical phenomena.     

Evolution of permeability and microstructure of experimentally-created shear zones in Neogene siliceous mudstones from Horonobe,Japan

We report experimental measurements of bulk permeability changes due to a shear zone that is induced in siliceous mudstones collected from the Koetoi and Wakkanai Formations, northern Hokkaido, which are known to show different relationships between fault/fracture distribution and groundwater flow. We evaluate distributions of volumetric deformation in the induced shear zones by using micro-focus X-ray computed tomography. Measured permeability evolution while achieving the peak axial stress for specimens differed for the samples of the two formations. Permeability did not change obviously during shear for the Koetoi Fm. specimens, but in the Wakkanai Fm. specimens, the bulk permeability increased by a factor of 2.5 after reaching the peak stress. The difference in permeability change in these experiments can explain the differences in relationships between in situ groundwater flow and fracture distribution for the two formations. Analyses of the X-ray images reveal that this difference should reflect the differences of the volumetric deformation in the induced shear zones. Pore collapse occurred in the shear zone in the Koetoi Fm. specimen, which leads to porosity reduction, whereas fracture damages developed in the Wakkanai Fm. specimen, increasing porosity. These differences in the microstructure may reflect differences in yielding criteria for these host rocks.     

Numerical Modeling of Pore Pressure Influence on Fracture Evolution in Brittle Heterogeneous Rocks

Rock is a heterogeneous geological material. When rock is subjected to internal hydraulic pressure and external mechanical loading, the fluid flow properties will be altered by closing, opening, or other interaction of pre-existing weaknesses or by induced new fractures. Meanwhile, the pore pressure can influence the fracture behavior on both a local and global scale. A finite element model that can consider the coupled effects of seepage, damage and stress field in heterogeneous rock is described. First, two series of numerical tests in relatively homogeneous and heterogeneous rocks were performed to investigate the influence of pore pressure magnitude and gradient on initiation and propagation of tensile fractures. Second, to examine the initiation of hydraulic fractures and their subsequent propagation, a series of numerical simulations of the behavior of two injection holes inside a saturated rock mass are carried out. The rock is subjected to different initial in situ stress ratios and to an internal injection (pore) pressure at the two injection holes. Numerically, simulated results indicate that tensile fracture is strongly influenced by both pore pressure magnitude and pore pressure gradient. In addition, the heterogeneity of rock, the initial in situ stress ratio (K), the distance between two injection holes, and the difference of the pore pressure in the two injection holes all play important roles in the initiation and propagation of hydraulic fractures. At relatively close spacing and when the two principal stresses are of similar magnitude, the proximity of adjacent injection holes can cause fracturing to occur in a direction perpendicular to the maximum principal stress.     

核废料地质处置概念库锚喷支护坑道热-水-应力耦合效应的二维离散元分析

假定一个核废料地质处置库位于具有一定水头的饱和节理岩体中,开挖完闭施作系统锚杆和喷混凝土支护。对坑道建造和一个50年期的热-水应力（T-H-M）耦合运营过程,使用UDEC程序进行数值模拟,分析无、有支护时近场围岩中的应力、变形、塑性区、温度、渗流的变化状态,以及不同场（温度、渗流、应力）耦合条件下的锚杆和喷混凝土中的承载情况。结果显示,喷混凝土和系统锚杆支护不仅具有常规的支护功能,并且可阻滞地下水从坑道表面的自由渗出,使得围岩中塑性区减小,裂隙水压力和温度升高;相比于应力单场作用的情况,在热-水-力耦合的条件下洞室围岩的稳定性下降,支护结构的受力状况变差。