渤海海峡跨海通道工程区海域三维地应力测试
Measurement of 3D in-situ stress in the sea area of trans-Bohai strait passage engineering region
王锦山 1彭华2
作者信息
- 1. 河北科技师范学院城市建设学院,河北秦皇岛 066004
- 2. 中国地质科学院地质力学研究所,北京 100081
- 折叠
摘要
跨渤海通道海域缺乏实测地应力基础数据,而海域钻探原位实测又承担着巨大风险与重重困难,为取得工程区现今地应力场特征第一手资料,利用以水压致裂地应力测量为主,以空心包体、非弹性应变恢复、差应变、声波各向异性法为辅的综合地应力测量技术,对研究区海域开展三维地应力测试与研究,建立了线性回归方程,得到了回归拟合曲线.结果表明,渤海海峡最大水平主应力σH、最小水平主应力σh与垂直主应力σV均随测试深度的增加呈线性增大规律;海峡南部地应力状态存在σH＞σh＞σv的关系,处于逆冲应力状态,应力场方向为NE,最大水平主应力大于垂直主应力,区域内构造力处于主导地位;海峡北部应力状态为σH＞σv＞σh,有利于走滑断层活动,应力场方向为NE,区域内构造力处于主导地位;整个工程区内地应力各分量值之间相差不大,远远小于区内断层活动应力值的下限,表明研究区目前处于稳定状态.研究结果符合一般地应力测量规律,测试流程符合地应力测试要求,测试数据可用于分析区域地应力状态.
Abstract
Trans-Bohai passage sea area lacks basic data on measured in-situ stress.Conducting in-situ measurements in this area is challenging and carries significant risks.To obtain firsthand data on the current in-situ stress field characteristics,a comprehensive in-situ stress measurement technology is employed.This technology primarily relies on hydraulic fracturing in-situ stress measurement,supplemented by methods such as hollow inclusion,inelastic strain recovery,differential strain,and acoustic anisotropy.Three-dimensional in-situ stress measurement and research are conducted in the sea area of the study region.A linear regression equation is established,and a regression fitting curve is obtained.The results reveal certain patterns:as the test depth increases in the Bohai strait,the maximum horizontal principal stress σH,minimum horizontal principal stress σh,and vertical principal stress σv all increase linearly with the increase of test depth.In the southern part of the strait,the in-situ stress state follows the relationshipσ H＞σh＞σ v,indicating a thrust stress state.The stress field direction is NE,with the maximum horizontal principal stress exceeding the vertical principal stress,suggesting dominance of tectonic forces in the region.In the northern part of the strait,the stress state is σH＞σv＞σh,which is conducive to strike-slip fault activity.The stress field direction remains NE,and tectonic forces dominate in the region.Throughout the entire engineering region,there is minimal difference in each component value of the in-situ stress.These values are significantly lower than the lower limit of the active stress value of faults in the area,indicating that the study area is currently in a stable state.These findings align with the general principles of in-situ stress measurement.The testing process adheres to the requirements of in-situ stress testing,and the obtained data can be used to analyze the regional in-situ stress state.
关键词
跨渤海海峡大通道/工程区海域三维地应力/综合测量技术Key words
trans-Bohai strait passage/3D in-situ stress in the sea area of engineering region/comprehensive measurement technology引用本文复制引用
基金项目
国家海洋地质专项(GZH01-07-3-2)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据