Comprehensive analysis on present tectonic stress field in Urumqi region
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摘要: 乌鲁木齐地处天山中段．震源机制解研究表明，北天山中段区域主压应力方向为N10deg;E左右，且具有自西向东逐渐东偏的特点．在乌鲁木齐地区，由中强地震震源机制解反演的主压应力方向为N15deg;——20deg;E；由断层滑动资料反演的乌鲁木齐周边构造应力场的主压应力方向为N17deg;W——N2deg;E．上述两种资料反演的乌鲁木齐构造应力场主压应力方向与北天山中段比较接近．在乌鲁木齐市周围，由小震综合断层面解得到的主压应力方向为N40deg;——46deg;E，与区域主压应力方向具有20deg;——30deg;的偏转；而由钻孔应力测量的主压应力方向为N55deg;E，这与小震综合断层面解主压应力方向相比又向东偏转10deg;——15deg;，与区域的主压应力方向偏转达30deg;——40deg;．上述结果表明，在乌鲁木齐逆断层－褶皱构造的前缘隆起区存在张性作用，其主压应力方向与区域主压应力方向近垂直．而在乌鲁木齐开展的钻孔应力测量结果进一步表明，在NNE向主压应力的背景中，叠加了浅部与之近垂直的压应力场，致使浅部主压应力方向偏向ENE. 这也可以解释为何乌鲁木齐市区ENE向的九家湾断层组表现为正断层性质．Abstract: Urumqi city is located in central part of northern piedmont of Tianshan mountain. The mean direction of principal compressive stress in central section of northern Tianshan deduced from the focal mechanism solutions is around N10deg;E, with a clear feature of gradual change from west to east. In the region of Urumqi city, the direction derived from focal mechanism solutions of moderate-strong earthquakes is N15deg;mdash;20deg;E.The principal stress direction found from fault striation inversion is N17deg;Wmdash;N2deg;E. The stress direction deduced from the above two data sets are basically in the variation range of the principal compressive stress in the central section of northern Tianshan. However, the stress direction inferred from composite fault-plane solutions of small earthquakes within 25 km of the Urumqi seismic station is N40deg;mdash;46deg;E, which shows a deviation of 20deg;mdash;30deg;from that of regional principal compressive stress. Nevertheless, the direction of maximum horizontal compressive stress measured in the boreholes in Urumqi city is around N55deg;E, which displays a further deviation of 10deg;mdash;15deg;, and its deviation from that of regional stress field is up to 30deg;mdash;40deg;. These phenomena indicate that a tension stress in the shallow layers in front part of the compressive fault-fold region has been superposed to the regional NNE-SSW trending compressive tectonic stress and makes the direction of local principal compressive stress turn to NEE-SWW. This is one of the causes why the normal faults, such as the Jiujiawan fault groups, were developed in Urumqi city.
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期刊类型引用(11)
1. 梁珍，乔国文，李治财，王涛，赵龙，曾召田. 中天山花岗岩深埋隧道高地应力测试及工程影响分析. 现代隧道技术. 2024(S1): 332-341 . 
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2. 李艳永，王成虎，朱皓清，乌尼尔. 北天山地区震源机制与构造应力场特征. 地震. 2020(02): 117-129 . 百度学术
3. 刘兆才，万永革，黄骥超，靳志同，杨帆，李瑶. 2017年精河M_S6.6地震邻区构造应力场特征与发震断层性质的厘定. 地球物理学报. 2019(04): 1336-1348 . 百度学术
4. 李艳永，王成虎，杨佳佳. 呼图壁地区震源机制解及构造应力场特征分析. 大地测量与地球动力学. 2018(12): 1246-1250 . 百度学术
5. 万永革. 联合采用定性和定量断层资料的应力张量反演方法及在乌鲁木齐地区的应用. 地球物理学报. 2015(09): 3144-3156 . 百度学术
6. 孙业君，刘红桂，江昊琳，詹小艳，王俊菲，丁烨，叶碧文. 江苏南部地区现今震源机制和应力场特征. 地震研究. 2015(02): 203-210 . 百度学术
7. 刘旭东，孙秉成，荣海. 乌东矿区地质断裂构造对冲击地压的影响. 内蒙古煤炭经济. 2015(06): 205-207 . 百度学术
8. 丁亮，高尔根，孙守才，邓晓果，刘骁. 天山活动地块地震的震源机制. 防灾科技学院学报. 2014(02): 42-48 . 百度学术
9. 蓝航. 近直立特厚两煤层同采冲击地压机理及防治. 煤炭学报. 2014(S2): 308-315 . 百度学术
10. 郑建常，王鹏，李冬梅，赵金花，徐长朋. 使用小震震源机制解研究山东地区背景应力场. 地震学报. 2013(06): 773-784 . 本站查看
11. 黄龙现，杨天鸿，李现光，郑超. 地应力场方向对巷道围岩稳定性的影响. 中国矿业. 2012(04): 105-107+118 . 百度学术
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