西山矿区是山西省采煤区的重要组成部分,为补充矿区地应力测试空白和研究掌握矿区地应力场分布规律与变化特征，采用小孔径水压致裂地应力测量装置，在西山矿区9个煤矿，完成59个测点的原位地应力测量，从地应力场类型、地应力量级、水平主应力方向以及侧压比等多角度分析表征地应力场分布规律等参量的变化特征，分析矿区煤系沉积岩地层不同岩性岩体水平主应力及侧压比随埋深的变化关系，研究西山煤矿区地应力场分布规律，探究岩性对矿区地应力场分布规律的影响。结果表明:西山矿区主要为中深部矿井，井下地应力场以水平应力为主，构造应力场占绝对主导优势，地应力量级主要为中等水平，低应力水平次之，地应力值随埋深增加而增大，但离散性也非常显著，埋深不仅决定地应力场类型，而且影响地应力量级;水平最大主应力方向呈NW向和NE向，主要为N5°W～N90°W和N6°E～N87°E，约各占50%;正断层带附近水平主应力呈明显增大变化特征，水平最大主应力方向发生扭转，为导致矿区地应力值异常和离散的主要影响因素;最大侧压比为0.80～4.23，其大小与地应力场类型相关，小于1为自重应力场，大于1为构造应力场，超过2水平应力完全占主导地位，平均侧压比为0.61～3.19，与埋深拟合曲线和霍克-布朗提出的曲线相似，但由于仅为西山特定煤矿区沉积岩地层测量数据故数值上存在明显差异;岩性不同岩体水平主应力值大小随埋深增加均增大，但应力增长梯度显现出差异性，岩性不同岩体两类侧压比随埋深增加均趋向于定值，但两类侧压比曲率大小呈现出明显的差异化特征，岩性仅为影响矿区地应力场分布规律的因素之一，很难依据单因素精确判定构造应力场的分布规律。

Xishan mining field is an important part of coal mining area in Shanxi Province.In order to make up the blank of in-situ stress measurement and to study the distribution law and variation characteristics of in-situ stress field,using a small-bore hydrofracturing in-situ stress measurement device,some geostress measurements were carried out at 59 sites in 9 coal mines in Xishan,the variation characteristics of the parameters,such as the type of in-situ stress field,the magnitude of in-situ stress,the direction of horizontal principal stress and the ratio of lateral pressure,which characterize the distribution law of in-situ stress field,were analyzed,the relationship between the horizontal principal stress and lateral pressure ratio of rock mass with different lithology to the sedimentary strata of coal measures and burial depth were also analyzed in Xishan mining area,to study the distribution law of in-situ stress field,and to explore the influence of lithology on the distribution law of in-situ stress field.The result shows that the coal mines are at a moderate depth in Xishan,the underground stress field is mainly tectonic stress field,the horizontal stress is absolutely dominant,the magnitude of in-situ stress is mainly medium level,and the low stress level is next,the in-situ stress increases with the buried depth,but the discrete type is also very significant,the buried depth not only determines the type of in-situ stress field,but also influences the magnitude of in-situ stress.The direction of the maximum horizontal principal stress are NW and NE,mainly N5°W~N90°W and N6°E~N87°E,each accounting for about 50%.The horizontal principal stress around the normal fault zone increases obviously,and the direction of the horizontal principal stress is reversed,which is the main influence factor of the abnormal and discrete ground stress value.The maximum lateral pressure ratio is 0.80-4.23,which is related to the type of in-situ stress field,less than 1 is the gravity stress field,and more than 1 is the tectonic stress field,and more than 2 horizontal stress is completely dominant.Average lateral pressure ratio is 0.61-3.19,the fitting curve of it and burial depth is similar to the curve proposed by Hoek-Brown,but because of the measured data of sedimentary rock strata in specific Xishan coal mining areas,there are obvious differences in values.The values of horizontal principal stress to different lithology rock mass all increase with the increase of burial depth,but the gradient of stress increase is different,the two types of lateral pressure ratio to different lithology rock mass all tend to be fixed with the increase of mining depth,but the curvatures of them show obvious difference,lithology is only one of the factors that affect the distribution of in-situ stress field in Xishan mining area,and it is difficult to assess the distribution characteristics of tectonic stress field accurately based on single factor.