Dizhi lixue xuebao (Jun 2023)
In-situ stress characteristics and rockburst tendency of surrounding rocks in the Shuiwangzhuang gold deposit, Zhaoyuan, Shandong province
Abstract
We carried out hydraulic fracturing in-situ stress measurements in an 1881-m deep borehole at the Shuiwangzhuang gold deposit and obtained the variation law of deep in-situ stress with depth in the mining area. The measurement results show that the maximum principal stress has an increasing linear trend with depth. The horizontal stress dominates the in-situ stress state within 800 m, and the vertical stress gradually transitions to the maximum principal stress with increasing depth. The maximum horizontal principal stress ranges from 11.22 to 45.69 MPa, the minimum horizontal principal stress from 7.28 to 36.17 MPa, and the vertical principal stress from 8.44 to 48.27 MPa; The direction of the maximum horizontal principal stress is NWW-trending. We analyzed the characteristics of the deep orebody’s in-situ stress according to the stress value and the direction of the maximum horizontal principal stress, which reveals that the deep in-situ stress of the Shuiwangzhuang mining area belongs to the generally low level in the Zhaoyuan–Laizhou area. We discussed the tendency of rockburst in the underground roadway during deep excavation under a high confining pressure environment based on rock mechanics parameters of drill cores, engineering rock grading standards, and elastic strain energy theory of rock bodies. The Shuiwangzhuang gold orebodies generally belong to the rockburst-free strata or strata with weak rockbursts. However, there is a strong rockburst tendency at depths such as 1102.78 m and 1379.40 m. The gold ore body is at a depth of 1680.40~1684.90 m, generally in the rockburst-free area. The above research results can provide an essential scientific basis for deep mine construction and mining design.
Keywords
