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山东地区地质构造环境十分复杂,历史上曾多次发生中强地震及强震。为深入了解该地区现今构造应力场特征及区域地壳应力积累水平,基于优化处理后的181组地应力实测数据,采用回归分析法全面分析了该地区地应力量值随深度的分布特征,并依据地壳应力积累理论,探讨了区域应力积累水平和地壳稳定性。结果表明,该地区地应力状态主要以σH>σh>σv型和σH>σv>σh型为主,应力状态类型与深度有一定关系;3个主应力σH,σh和σv均随深度呈近似线性增加的关系,应力变化梯度值分别为0.024 2,0.018 0,0.025 8;3个侧压系数KH,Kh和Kav随深度呈近似双曲线分布,随着深度的增加分别向1.46,0.89,1.17趋近;水平差应力相对大小μd更接近于线性分布,随着深度的增加趋向于0.24;最大水平主应力优势方向整体表现为NWW-SEE向,但NEE-SWW向也占有较大比例,优势方位统计结果与世界应力图2016及板块间作用相吻合;沂沭断裂带西侧区域最大水平主应力优势方向整体呈NEE-SWW向,而其东侧区域整体呈NWW-SEE向。mm能较好地反映地壳应力积累能力,mm值主要集中在0.3~0.5,0.2~0.3范围内,该地区的应力积累水平整体上处于中低程度,地壳浅层处于相对稳定状态。逆断型应力状态的mm值主要集中在0.2~0.3范围内,应力积累水平以较低程度为主;走滑型应力状态的mm值主要集中在0.3~0.5范围内,应力积累水平以中等程度为主。
The geological tectonic environment in Shandong is very complicated. There have been many moderate-strong earthquakes and strong earthquakes in history. In order to deeply understand the tectonic stress field characteristics and regional crustal stress accumulation level in this area, based on the measured data of 181 sets of ground stress after optimization, the distribution characteristics of the ground stress with depth in this area are analyzed comprehensively by regression analysis. Crustal stress accumulation theory, discusses the regional level of stress accumulation and crustal stability. The results show that the main stress states of the area are mainly σH> σh> σv and σH> σv> σh, and the stress state types have a certain relationship with depth. The three principal stresses σH, σh and σv are approximately linear with depth Increasing, and the gradient values of stress change are 0.024, 2.0.018 and 0.0258 respectively. The three lateral pressure coefficients KH, Kh and Kav are nearly hyperbolic distribution with depth, with the depth increasing to 1.46,0.89 and 1.17 respectively The horizontal relative stress μd is closer to the linear distribution and tends to 0.24 with the depth increasing. The predominant direction of the maximum horizontal principal stress is NWW-SEE, but the NEE-SWW direction occupies a larger proportion. The dominant azimuth The statistical results are consistent with the results of the world stress map 2016 and the plates. The predominant direction of the maximum horizontal principal stress in the west of the Yishu fault zone is generally NEE-SWW, whereas the east side of the region is NWW-SEE. mm can better reflect the crustal stress accumulation ability. The values of mm are mainly concentrated in the range of 0.3-0.5 and 0.2-0.3. The stress accumulation level in this area is generally at a low level and the shallow crust is in a relatively stable state. The value of mm in the thrust stress state mainly lies in the range of 0.2-0.3, and the stress accumulation level is mainly at a relatively low level. The values of the mm value of the strike-slip stress state are mainly concentrated in the range of 0.3-0.5. The stress accumulation level is moderately Mainly.