水工隧洞外文翻譯--輸水隧洞的應(yīng)力狀態(tài)和可能的擠壓變形的預(yù)測(cè)分析（英文）

1、Predictive analysis of stress regime and possible squeezing deformation for super-long water conveyance tunnels in PakistanWang Chenghu ?, Bao LinhaiKey Laboratory of Crustal Dynamics, Institute of Crustal Dynamics, CEA,

2、 Beijing 100085, Chinaa r t i c l e i n f oArticle history:Received 10 February 2014Received in revised form 17 April 2014Accepted 5 June 2014Available online 14 November 2014Keywords:Super-long water conveyance tunnelIn

3、-situ stress stateSqueezing deformationPrediction analysisKohala hydropower planta b s t r a c tThe prediction of the stress field of deep-buried tunnels is a fundamental problem for scientists andengineers. In this stud

4、y, the authors put forward a systematic solution for this problem. Databases fromthe World Stress Map and the Crustal Stress of China, and previous research findings can offer predictionof stress orientations in an engin

5、eering area. At the same time, the Andersonian theory can be used toanalyze the possible stress orientation of a region. With limited in-situ stress measurements, theHoek–Brown Criterion can be used to estimate the stren

6、gth of rock mass in an area of interest by utilizingthe geotechnical investigation data, and the modified Sheorey’s model can subsequently be employed topredict the areas’ stress profile, without stress data, by taking t

7、he existing in-situ stress measurements asinput parameters. In this paper, a case study was used to demonstrate the application of this systematicsolution. The planned Kohala hydropower plant is located on the western ed

8、ge of Qinghai–Tibet Plateau.Three hydro-fracturing stress measurement campaigns indicated that the stress state of the area is SH > -Sh > SV or SH > SV > Sh. The measured orientation of SH is NEE (N70.3?–89?E

9、), and the regional orientation ofSH from WSM is NE, which implies that the stress orientation of shallow crust may be affected bylandforms. The modified Sheorey model was utilized to predict the stress profile along the

10、 water sewagetunnel for the plant. Prediction results show that the maximum and minimum horizontal principal stres-ses of the points with the greatest burial depth were up to 56.70 and 40.14 MPa, respectively, and thestr

11、esses of areas with a burial depth of greater than 500 m were higher. Based on the predicted stressdata, large deformations of the rock mass surrounding water conveyance tunnels were analyzed. Resultsshowed that the larg

12、e deformations will occur when the burial depth exceeds 300 m. When the burialdepth is beyond 800 m, serious squeezing deformations will occur in the surrounding rock masses, thusrequiring more attention in the design an

13、d construction. Based on the application efficiency in this casestudy, this prediction method proposed in this paper functions accurately.? 2014 Published by Elsevier B.V. on behalf of China University of Mining E1 and

14、E2 the elastic moduliof the rock; z1 and z2 the burial depths. Initially, Sheorey did not clarify the difference between the elastic modulus of the rockspecimen and the deformation modulus of the rock masses. He subseque

15、ntly realized the impacts on horizontal stresses from theelastic modulus, and investigated this further, however, this prob- lem remains unsolved [12]. According to research findings of Jinget al., Wang et al., and Sheor

16、ey et al., the ratio of the horizontal stress to the vertical stress approaches a constant at a certain depthin the crust; i.e., E(z) in Eq. (1) increases slowly and will not be lower than a constant [12–14]. In addition

17、, Sheorey’s model is astatic one, not taking into account tectonic stresses, however,measured in-situ stresses contained tectonic components. Thus, Sheorey’s theoretical model is a good fitting tool to simulate theprofil

18、e of crustal stresses versus depth. Therefore, if this model is used to predict the real in-situ stress profile, some modificationshave to be made. Here we modified two aspects: (1) a tectonic com- ponent was added to th

19、e Eq. (1); and (2) the deformation modulusof a rock mass was used to replace the elastic modulus of the rock specimen [11]. Hoek and Diederichs researched in detail the defor-mation modulus of rock masses and established

20、 a relationship between the deformation modulus of the in-situ rock mass andthe GSI (geological stress index) on the basis of rigorous statistical analysis [15]. This equation can remedy the flaw of Sheorey’s modelin the

21、 elastic modulus of rock specimen during the prediction of stress magnitudes.Erm ¼ 1000 1 ? D=21 þ eð75þ25D?GSIÞ=11? ?ð3Þwhere Erm refers to the deformation modulus of the in-situ rock

22、mass; D is the disturbance index of rock mass having a values inthe range of 0–1, depending on the degree of disturbance from external factors, such as explosion, excavation, and unloading. Substitute Eq. (3) into Eq. (2

23、) to get:k2 ¼ k10:25 þ Ct2ðzÞ þ 7Erm2ð0:001 þ 1=z2Þ0:25 þ Ct1ðzÞ þ 7Erm1ð0:001 þ 1=z1Þ ð4Þwhere for the first and second areas of inter

24、est Erm1 and Erm2 are thedeformation moduli of rock masses; Ct1 and Ct2 the constant tectonic stress components in the rock masses. Eq. (4) is themodified Sheorey model, used to predict and analyze the stress magnitude.

25、The modified model contains two variables, depth (z)and deformation modulus of the rock mass (Erm). Erm is at the same time a function of depth and contains a wealth of information abouta rock mass, such as lithology, di

26、scontinuities and so on. The modified model can therefore fit and predict the profile of stressesversus depth and location. k also implies some information about the stress state and data relevant to the Anderson’s theor

27、y. As suchit can be used to predict the stress profile along the axis of a deeply- buried tunnel. The last step involves adjusting and calibrating the predicted stress magnitude and directions with reference to the geote

28、chnical investigation data. For example, the stress directions may deviate near a small-scale fault or vein, and the stress magnitudes may be higher in the core of a geological fold compared with other com- mon areas. Fi

29、ndings in the two classic references can be used as a guide book for such adjustments and calibrations [1,7]. However, for general discontinuities, the calibrations are unnecessary because the strength of rock mass in Eq

30、. (4) has taken their impacts into account and minor impacts on the direction of stress regime can generally be ignored.2.2. Analytical method for squeezing deformationThe rock mass around water conveyance tunnels is mai

31、nly soft rock and the burial depth of the tunnel means there is a high possibility for squeezing deformations to occur. For this reason it is necessary to analyze and predict possible deformations under34°15 34°

32、;25 34°3073°25 73°30 73°35 73°40 73°45 73°5034°10 34°05HartinDamHFTLangeprahNKohala Power generation houseWater conveyance tunnelJiram faultFig. 2. Geographical location of th