基于采空区压实效应的工作面开采全过程模拟

Numerical simulation for whole process of longwall mining on the basis of goaf compaction effect

为探究孤岛工作面开采时覆岩破断、运移和矿压显现规律,利用FLAC3D Fish语言开发了数值算法,基于采空区压实理论和双屈服模型,提出一种孤岛工作面推进过程中覆岩破断演化、垮落带岩体的压实效应和采动静载、动载响应数值模拟方法.采用该方法对朝阳煤矿3108孤岛工作面采动全过程及其动静载演化机制进行了数值模拟,所得结果与现场实际具有较好的一致性.结果表明:由于两侧采空区工作面长度较小(70 m),开采后覆岩垮落不充分,垮落带和裂隙带演化高度有限,约为30.98和66.91 m;动载主要来源于顶板破断释放能量,震源和覆岩裂隙带演化的最大高度基本一致,其震源包络线与裂隙带的发育范围吻合度较高.

To study the fracturing and movement of overlying strata and underground pressure law during isolated panel mining, a numerical method using Fish language developing FLAC3 D, which is based on the goaf compaction theory and the double-yield constitutive model, is proposed to investigate the evolution of overlying strata, the goaf compaction effect, static stress and dynamic response of dynamic load in island longwall panel operation. This method is used to simulate the mining process of island panel 3108 in Chaoyang coal mine, and the results correlate well with the field observation. As the small gob width(70 m) on both sides, the overlying strata height is limited, and the cave-in zone and fracture zone are 30.98 and 66.91 m high, respectively. The main source of dynamic loads is originated from roof fracturing, and both height and envelope of the mine tremors are well consistent with the fracture zone. The proposed method can give insight into numerical analyses on mining-induced static and dynamic loads in burst-prone panels.