THE STATE OF THE IN-SITU STRESS AND FAULT STABILITY EVALUATION OF THE PENGLAI COAST
-
摘要: 为查明蓬莱近海岸的地应力状态,开展了2个钻孔(深度小于200m)的水压致裂地应力测量工作,并与长岛附近海域3个钻孔的地应力状态进行了对比,采用回归分析方法,分析了该地区地应力随深度变化的特征,结合最大剪应力与平均主应力之比(μm)和侧压力系数(K')探讨了研究区的断层稳定性。结果表明:蓬莱近海岸和长岛海域的地应力状态基本一致,最大水平主应力方向主要表现为北东东至东西向,这与华北的区域应力场相一致;水平应力的梯度大于环渤海圈的平均地应力梯度;研究区浅部三向主应力相对大小以SH > Sh > Sv为主,这有利于逆断层的活动;研究区K'值和μm值均较高,分布区间分别为:2.76~3.98和0.47~0.59;陆区断层与区域应力方向均以较大角度相交,处于稳定的状态;海域的北西西向和北东向断层与区域应力场的方向夹角较小,如果区域应力持续增强,将有利于走滑断层的活动,这与震源机制以走滑型地震为主相符。研究结果对研究区内断层稳定性的评价和重大工程的设计及施工都具有重要参考意义。Abstract: In order to find out the in-situ stress state near the Penglai coast, hydraulic fracturing in-situ stress measurement was conducted in two boreholes (less than 200 meters in depth). The results were compared with the in-situ stress state of three boreholes off Changdao. Regression analysis was adopted to analyze the variation of in-situ stress with depth in this area. Fault stability in the study area was discussed combined with the ratio (μm) of maximum shear stress to average principal stress and lateral pressure coefficient(K'). The results show that the in-situ stress state of the Penglai coast is basically the same with that of Changdao, with the direction of the maximum horizontal principal stress being mainly NEE-EW which is consistent with the regional stress field in north China. The gradient of horizontal stress is greater than the average in-situ stress gradient of Bohai Rim. The relative magnitude of the three-dimensional principal stress in the shallow part of the study area is mainly SH > Sh > Sv which is conducive to the movements of the reverse faults. The values of both the study area and μm are high whose distribution intervals are 2.76~3.98 and 0.47~0.59 respectively. The land area faults and regional stress directions intersect at larger angles and are in a stable state; the angles between the NWW and NE faults of the sea area and the regional stress fields are smaller. If the regional stress continues to increase, it will be conducive to the movements of the strike-slip faults. This may be the primary reason for the frequent earthquakes of Changdao which is consistent with the fact that the focal mechanism of the earthquakes is mainly strike-slip. The research results are of great significance not only to the evaluation of fault stability in the study area but also to the design and construction of major projects.
-
Key words:
- Bohai Strait cross-sea Channel /
- Penglai Coast /
- Changdao /
- In-situ stress state /
- Byerlee's law /
- fault stability
-
表 1 钻孔的地应力测量结果
Table 1. Results of in-situ stress measurement in boreholes
钻孔编号 岩性 序号 测量深度/m 主应力值/MPa 方位/° P0/MPa μm KHmax Ka K′ SH Sh Sv 花岗岩 1 71.87 7.36 4.9 1.9 0.65 0.69 3.87 3.23 5.37 花岗岩 2 81.27 6.15 4.3 2.15 0.74 0.59 2.86 2.43 3.84 花岗岩 3 109.63 8.43 5.07 2.9 1.02 0.60 2.91 2.33 3.94 ZK7 花岗岩 4 129.08 11.32 6.86 3.42 NW80° 1.21 0.64 3.31 2.66 4.57 花岗岩 5 146.25 10.39 6.23 3.87 NE79° 1.38 0.57 2.68 2.15 3.62 花岗岩 6 162.44 9.25 5.79 4.3 1.54 0.47 2.15 1.75 2.79 花岗岩 7 178.8 13.71 8.05 4.73 NE78° 1.7 0.60 2.90 2.30 3.96 花岗岩 8 192.3 13.24 8.08 5.09 1.83 0.56 2.60 2.09 3.50 花岗岩 1 73.59 9.28 5.72 1.95 0.66 0.74 4.76 3.85 6.68 花岗岩 2 83.02 8.08 4.61 2.2 0.75 0.67 3.67 2.88 5.06 ZK13 花岗岩 3 92.68 9.07 5.41 2.45 0.84 0.67 3.70 2.96 5.11 花岗岩 4 102.06 8.26 5.5 2.7 NE63° 0.94 0.61 3.06 2.55 4.16 花岗岩 5 138.78 8.52 5.56 3.67 1.30 0.51 2.32 1.92 3.05 花岗岩 6 146.52 10.7 6.84 3.88 NE71° 1.37 0.58 2.76 2.26 3.72 花岗岩 7 156.22 7.55 5.03 4.13 NE75° 1.47 0.39 1.83 1.52 2.29 花岗岩 8 173.36 11.36 6.9 4.59 1.64 0.53 2.47 1.99 3.29 注:Sv-垂直应力; Sv的计算取上覆岩石容重2.70 g/cm3;P0-静水压力。Ka-平均水平主应力与垂直应力之比;KHmax最大水平主应力与垂直主应力之比,K′-有效应力条件下的KHmax;μm-最大剪应力与平均主应之比。 -
[1] HAST N. The state of stress in the upper part of the earth's crust[J]. Tectonophysics, 1969, 8(3):169-211. doi: 10.1016/0040-1951(69)90097-3 [2] LIAO C T, ZHANG C S, WU M L, et al. Stress change near the Kunlun fault before and after the Ms 8.1 Kunlun earthquake[J]. Geophysical Research Letters, 2003, 30(20):2027. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=10.1029/2003GL018106 [3] 郭啟良, 王成虎, 马洪生, 等.汶川Ms8.0级大震前后的水压致裂原地应力测量[J].地球物理学报, 2009, 52(5):1395-1401. doi: 10.3969/j.issn.0001-5733.2009.05.029GUO Qiliang, WANG Chenghu, MA Hongsheng, et al. In-situ hydro-fracture stress measurement before and after the Wenchuan Ms8.0 earthquake of China[J]. Chinese Journal of Geophysics, 2009, 52(5):1395-1401. (in Chinese with English abstract) doi: 10.3969/j.issn.0001-5733.2009.05.029 [4] RALEIGH C B, HEALY J H, BREDEHOEFT J D. An experiment in earthquake control at Rangely, Colorado[J]. Science, 1976, 191(4233):1230-1237. doi: 10.1126/science.191.4233.1230 [5] ZANG A, STEPHANSSON O. Stress field of the earth's crust[M]. Netherlands:Springer, 2010. [6] 秦向辉, 陈群策, 孟文, 等.大地震前后实测地应力状态变化及其意义:以龙门山断裂带为例[J].地质力学学报, 2018, 24(3):309-320. http://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20180303&journal_id=dzlxxbQIN Xianghui, CHEN Qunce, MENG Wen, et al. Evaluating measured in-situ stress state changes associated with earthquakes and its implications:a case study in the longmenshan fault zone[J]. Journal of Geomechanics, 2018, 24(3):309-320. (in Chinese with English abstract) http://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20180303&journal_id=dzlxxb [7] 王艳华, 崔效锋, 胡幸平, 等.基于原地应力测量数据的中国大陆地壳上部应力状态研究[J].地球物理学报, 2012, 55(9):3016-3027. http://d.old.wanfangdata.com.cn/Periodical/dqwlxb201209020WANG Yanhua, CUI Xiaofeng, HU Xingping, et al. Study on the stress state in upper crust of China mainland based on in-situ stress measurements[J]. Chinese Journal of Geophysics, 2012, 55(9):3016-3027. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/dqwlxb201209020 [8] TSUKAHARA H, IKEDA R, OMURA K. In-situ stress measurement in an earthquake focal area[J]. Tectonophysics, 1996, 262(1-4):281-290. doi: 10.1016/0040-1951(96)00014-5 [9] 王泽皋, 赵明淳, 姚殿义, 等.华北强震前后的大型震群活动[J].山西地震, 1986, (3):11-15. http://www.cnki.com.cn/Article/CJFDTOTAL-SXDZ198603004.htmWANG Zegao, ZHAO Mingchun, YAO Dianyi, et al. Large-scale earthquake swarm activities before and after the strong earthquakes in North China[J]. Shanxi Earthquake, 1986, (3):11-15. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-SXDZ198603004.htm [10] 苏鸾声.长岛地区分维结构变化与区域震活动关系及短临前[J].地震研究, 1993, 16(1):33-40.SU Luansheng. Relationship between the fractal structure variation in Changdao area and the areal seismicity and short-term and impending precursor feature[J]. Journal of Seismological Research, 1993, 16(1):33-40. (in Chinese with English abstract) [11] 中国地震台网中心.中国地震目录.[DB/OL]. http://www.ceic.ac.cn/speedsearch, 2017.China Earthquake Network Center. China Seismological Catalogue.[DB/OL]. http://www.ceic.ac.cn/speedsearch, 2017. [12] 李翠芹, 郑建常, 戴宗辉.山东长岛M3.9震群序列特征及发震构造探讨[J].国际地震动态, 2017, (8):93. doi: 10.3969/j.issn.0253-4975.2017.08.071LI Cuiqin, ZHENG Jianchang, DAI Zonghui. Sequence characteristics and seismogenic structure of M3.9 swarm in Changdao, Shandong[J]. Recent Developments in World Seismology, 2017, (8):93. (in Chinese) doi: 10.3969/j.issn.0253-4975.2017.08.071 [13] 郑红霞, 张训华, 赵铁虎, 等.渤海海峡及周边地应力分布规律与应力积累研究[J].岩石力学与工程学报, 2017, 36(2):357-369. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb201702008ZHENG Hongxia, ZHANG Xunhua, ZHAO Tiehu, et al. Geostress distribution and stress accumulation in Bohai strait and adjacent area[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(2):357-369. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb201702008 [14] 李鹏, 郭奇峰, 刘洪涛, 等.山东地区现今地应力场特征与应力积累水平分析[J].岩石力学与工程学报, 2017, 36(9):2220-2231. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb201709015LI Peng, GUO Qifeng, LIU Hongtao, et al. Characteristics of current in-situ stress field and stress accumulation in Shandong region[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(9):2220-2231. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb201709015 [15] 索艳慧, 李三忠, 刘鑫, 等.中国东部NWW向活动断裂带构造特征:以张家口:蓬莱断裂带为例[J].岩石学报, 2013, 29(3):953-966. http://d.old.wanfangdata.com.cn/Periodical/ysxb98201303017SUO Y H, LI Sanzhong, LIU Xin, et al. Structural characteristics of NWW-trending active fault zones in East China:A case study of the Zhangjiakou-Penglai Fault Zone[J]. Acta Petrologica Sinica, 2013, 29(3):953-966. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/ysxb98201303017 [16] 王志才, 邓起东, 晁洪太, 等.山东半岛北部近海海域北西向蓬莱-威海断裂带的声波探测[J].地球物理学报, 2006, 49(4):1092-1101. doi: 10.3321/j.issn:0001-5733.2006.04.022WANG Zhicai, DENG Qidong, CHAO Hongtai, et al. Shallow-depth sonic reflection profiling studies on the active Penglai-Weihai Fault zone offshore of the northern Shandong peninsula[J]. Chinese Journal of Geophysics, 2006, 49(4):1092-1101. (in Chinese with English abstract) doi: 10.3321/j.issn:0001-5733.2006.04.022 [17] 王华林, 胡超, 王纪强, 等.烟台市及其邻近地区活断层地震危险性评价[J].震灾防御技术, 2015, 10(2):211-226. http://d.old.wanfangdata.com.cn/Periodical/zzfyjs201502002WANG Hualin, HU Chao, WANG Jiqiang, et al. The seismic risk assessment on active faults in Yantai city and its adjacent area[J]. Technology for Earthquake Disaster Prevention, 2015, 10(2):211-226. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/zzfyjs201502002 [18] HAIMSON B C, CORNET F H. ISRM Suggested Methods for rock stress estimation-Part 3:hydraulic fracturing (HF) and/or hydraulic testing of pre-existing fractures (HTPF)[J]. International Journal of Rock Mechanics & Mining Sciences, 2003, 40(7-8):1011-1020. [19] 李兵, 李兵岩, 张策, 等.广西盆地东北部的地应力分布特征[J].岩石力学与工程学报, 2017, 36(S1):3475-3484. http://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2017S1041.htmLI Bing, LI Bingyan, ZHANG Ce, et al. Distribution characteristics of the crustal stress in the northeast of Guangxi Basin[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(S1):3475-3484. (in Chinese with English abstract) http://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2017S1041.htm [20] 张鹏, 孙治国, 王秋宁, 等.木寨岭深埋隧道北段地应力测量与围岩稳定性分析[J].地质力学学报, 2017, 23(6):893-903. http://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20170610&journal_id=dzlxxbZHANG Peng, SUN Zhiguo, WANG Qiuning, et al. In-situ stress measurement and stability analysis of surrounding rocks in the north section of deep buried tunnel in muzhailing[J]. Journal of Geomechanics, 2017, 23(6):893-903. (in Chinese with English abstract) http://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20170610&journal_id=dzlxxb [21] ZOBACK M D. Reservoir geomechanics[M]. Cambridge:Cambridge University Press, 2007:1-332. [22] 许忠淮, 汪素云, 黄雨蕊, 等.由大量的地震资料推断的我国大陆构造应力场[J].地球物理学报, 1989, 32(6):636-647. doi: 10.3321/j.issn:0001-5733.1989.06.004XU Zhonghuai, WANG Suyun, HUANG Yurui, et al. The tectonic stress field of Chinese continent deduced from a great number of earthquakes[J]. Acta Geophysica Sinica, 1989, 32(6):636-647. (in Chinese with English abstract) doi: 10.3321/j.issn:0001-5733.1989.06.004 [23] 刘方斌, 曲均浩, 李国一, 等.山东长岛震群震源机制解一致性参数时空演化特征[J].地震工程学报, 2018, 40(5):1034-1041. doi: 10.3969/j.issn.1000-0844.2018.05.1034LIU Fangbin, QU Junhao, LI Guoyi, et al. Spatial-temporal characteristics of the focal mechanism solutions consistency parameter of Changdao earthquake swarm[J]. China Earthquake Engineering Journal, 2018, 40(5):1034-1041. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-0844.2018.05.1034 [24] BROWN E T, HOEK E. Trends in relationships between measured in-situ, stresses and depth[J]. International Journal of Rock Mechanics and Mining Science & Geomechanics Abstracts, 1978, 15(4):211-215. doi: 10.1016/0148-9062(78)91227-5 [25] 高建理, 丁健民, 梁国平, 等.中国海区及其邻域的原地应力状态[J].地震学报, 1992, 14(1):17-28. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXB199201002.htmGAO Jianli, DING Jianmin, LIANG Guoping, et al. In-situ stress state in China sea area and its adjacent areas[J]. Acta Seismologica Sinica, 1992, 14(1):17-28. (in Chinese with English abstract) http://www.cnki.com.cn/Article/CJFDTOTAL-DZXB199201002.htm [26] 詹润, 朱光, 杨贵丽, 等.渤海海域新近纪断层成因与动力学状态[J].地学前缘, 2013, 20(4):151-165. http://d.old.wanfangdata.com.cn/Periodical/dxqy201304012ZHAN Run, ZHU Guang, YANG Guili, et al. The genesis of the faults and the geodynamic environment during Neogene for offshore of the Bohai sea[J]. Earth Science Frontiers, 2013, 20(4):151-165. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/dxqy201304012 -