赵固一矿巷道复合顶板岩层结构类型与稳定性数值模拟分析

Rock Structure Type and Numerical Simulation Analysis on Stability of Roadway Compound Roof in Zhaogu No. 1 Mine

巷道复合顶板稳定性与软硬岩在巷道顶板的位置、薄厚和组合情况密切相关,本文采用现场实测、理论分析和数值模拟方法,分析了赵固一矿巷道复合顶板岩层结构类型,研究了不同岩层组合巷道顶板破坏特征与破断规律。研究表明:巷道复合顶板按岩层层位和组合情况可划分为单一软岩、下硬上软、下软上硬和软硬互层4种总结构类型,按岩层厚度继续划分为单一厚软、厚软厚硬、薄软厚硬、薄硬厚软、厚硬薄软和软硬薄多层相间6种亚结构类型。对于单一软岩和厚软厚硬顶板,垮落后冒顶形态呈圆锥形,紧邻其上部软岩形成外形如梁,实质是"铰接拱形"的平衡结构,最终趋于稳定;对于薄软厚硬和软硬薄多层相间顶板,垮落后冒顶形态呈平顶形,紧邻其上部硬岩由于自身承载能力强,最终趋于稳定;对于薄硬厚软和厚硬薄软顶板,无垮落现象,若硬岩继续变薄、巷道跨度加大或埋深增加,应注意监测和及时补强。基于赵固一矿已掘和未掘巷道顶板岩层结构类型,能够对现有的支护形式与支护参数进行评价和修正,保证掘采期间巷道顶板稳定。

The stability of roadway compound roof is closely related to the location,thickness and composition of soft-hard rocks in roadway compound roof.The paper used the methods of field measurement,theoretical analysis and numerical simulation to analyze strata structure type of roadway compound roof in Zhaogu No.1 Mine,and study failure characteristics and rupture regularity of different strata combination of roadway roof.The study results show that roadway compound roof can be classified into four general structure types:the single-soft rock,lower-hard upper-soft,lower-soft upper-hard and soft-hard alternation according to the location and composition of strata.It is further classified into six sub-structure types:the single thick-soft,thick-soft thick-hard,thin-soft thick-hard,thin-hard thick-soft,thick-hard thin-soft and thin-soft-hard alternation according to the strata thickness.For the single-soft and thick-soft thick-hard roof,the shape after roof fall is conical,which is next to its upper part soft rock and forms the shape of beam.It is essentially'articulated arch'balanced structure,which eventually tends to be stable.For the thin-soft thick-hard and thin-soft-hard alternation roof,the shape after roof fall is flat.The upper hard rock tends to be stable because of its strong bearing capacity.For the thin-hard thick-soft and thick-hard thin-soft roof,there is no caving phenomenon.If the hard rock continues to become thinner,the roadway span increases or the buried depth increases,it is attention to monitoring and timely reinforcement.Based on the rock structure types of roadway roof which has been excavated and unexcavated in Zhaogu No.1 Mine,the existing supporting forms and supporting parameters can be evaluated and modified,and can ensure the stability of roadway roof during excavation.