地应力测试数据甄别综合分析方法研究

 由于当前的地应力测试技术水平和实际工程岩体赋存地质条件的复杂性，地应力测试成果往往存在相当的误差；且地应力实测数据这一基础信息的质量和精度将直接影响地应力场量化模型的可靠性。鉴于此，提出结合工程区域宏观构造地质背景、地应力测试成果解析、工程现场破坏现象力学定性分析等多种手段对地应力测试数据进行科学分析和筛选的综合研究方法。首先，基于工程区域地质构造背景和局部地形地貌等影响因素形成对工程区域地应力场的宏观判断和总体认识；然后，采用全空间赤平投影方法和典型特征平面投影应力解析对地应力测点应力张量特征进行全面的量化分析，并与前期勘探平硐出现的破坏现象的力学定性分析成果进行对比研究和印证，从而对地应力测试结果的代表性和可靠性进行科学的甄别，筛选出能够从宏观上体现工程区域地应力场分布特征的测点进行初始应力场回归分析。采用上述研究思路对西南深切河谷地区一大型水电站坝址区地应力场分布特征进行分析，利用建立的初始应力场数值量化模型模拟实际施工过程预测的应力集中部位，与工程岩体实际发生的应力诱导型破坏部位有较好的一致性。

COMPREHENSIVE ANALYSIS METHOD FOR VALIDATING GEOSTRESS MEASUREMENT DATA

Owing to the current measurement technical level of geostress and complexity of geological conditions for actual rock mass,validity of measured results might be suspected;and the quality and precision of measured data of geostress as basic information will directly affect the reliability of quantitative model of geostress field.A comprehensive analysis method has been put forward to study the reliability and validity of measured data of geostress.The method combines with macrotectonic geological background in project area,geostress measurement data interpretation,mechanical qualitative analysis of rock mass failure phenomenon.Firstly,influences of comprehensive geological tectonic background and local geomorphology have been considered to form overall impression and macroscopical judgment of geostress field in project area.Then,full-space stereoprojection method and typical plane stress projection method have been used to quantitatively study the characteristics of stress tensor of geostress measuring point acquired through measurements.Comparative study will be conducted on the result mentioned above and the mechanical qualitative analysis results of certain rock mass failure phenomenon at exploration adit.So,measured data,which are assumed to be representative and reliable and can reflect geostress field in project area,are selected for the regression analysis of initial geostress field.By using this method,the distribution characteristics of geostress field at dam site of a large hydropower station,located in deeply incised river valley area of Southwest China,has been analyzed.The stress concentration position predicted by the established numerical quantitative model of initial geostress field and actual stress-induced failure parts have good consistency.