针对巨厚松散层与不等厚基岩下覆岩结构运动演化机理及破坏规律不明晰的问题, 以某矿3301工作面为工程背景, 采用物理模拟、数值模拟及理论分析等研究方法, 揭示了巨厚松散层与不等厚基岩条件下的覆岩运动演化过程、垮落充填特征及联动破坏机理, 建立了考虑巨厚松散层与不等厚基岩联动演化效应的覆岩运移模型和迹线估算方程。研究结果表明: ①基岩厚度由薄到中厚再到正常厚度时, 破坏边界形态演化过程为“对称梯形”→“不对称类梯形”→“半马鞍形”; 松散层运移在不等厚基岩控制下呈现出“对称漏斗”→“倾斜漏斗”→“斜底漏斗”动态变化。②薄基岩以塑性破坏为主, 垮落后无规则充填采空区且碎胀效应不明显, 松散层运移活跃期长, 导致地表下沉较大; 中厚基岩介于塑性破坏和块式破断之间, 能短暂形成不稳定结构, 对松散层运移起一定的支撑和限制作用; 正常厚度基岩发生“梁式”破断, 覆岩形成稳定的“铰接、悬臂”结构, 巨厚松散层能给下方裂隙或垮落的基岩造成更大压应力, 从而导致垮落带、裂隙带等较常规地层条件更加发育。③以3301工作面为实例, 估算了不同开采阶段的覆岩破坏迹线, 计算出地表沉降范围为1551.46 m, 与实测值相比, 误差为7.6%。④提出了限高或充填开采、巷道注浆加固、提高巷道支护体的让压能力及增强支护系统的兼容性等控制对策。

To address the unclear mechanisms of overburden movement, evolution, and failure under conditions of ultra-thick loose layers and uneven-thickness bedrock, the 3301 panel of a specific mine was selected as the engineering case study. Using physical simulation, numerical simulation, and theoretical analysis, this study investigates the overburden movement process, collapse and filling characteristics, and linkage failure mechanisms under these conditions. An overburden migration model and a trace estimation equation are proposed, accounting for the interactive evolution effects of ultra-thick loose layers and uneven-thickness bedrock. The findings are as follows: ① As bedrock thickness increases from thin to medium-thick to normal thickness, the failure boundary evolves from "symmetric trapezoid" to "asymmetric quasi-trapezoid" to "semi-saddle" shapes. Under the control of uneven-thickness bedrock, the movement of loose layers dynamically changes from a "symmetric funnel" to an "inclined funnel" to a "tilted-bottom funnel." ② Thin bedrock primarily undergoes plastic failure, resulting in irregular filling of goafs after collapse and minimal fragmentation-expansion effects. The prolonged active movement period of the loose layers causes significant surface subsidence. Medium-thick bedrock experiences characteristics between plastic failure and block-type fracturing, forming temporarily unstable structures that provide partial support and restriction on loose layer movement. In contrast, normal-thickness bedrock undergoes "beam-type" fracturing, with the overburden forming stable "hinged and cantilevered" structures. The ultra-thick loose layer applies greater compressive stress to the fractured or collapsed bedrock below, resulting in more pronounced development of collapse and fracture zones compared to conventional strata conditions. ③ Using the 3301 panel as an example, the overburden failure traces at different mining stages were estimated, and the calculated surface subsidence area was 1551.46 m², with a deviation of 7.6% from the measured value. ④ Control strategies are proposed, including height-limited or backfill mining, roadway grouting reinforcement, increasing the yielding capacity of roadway supports, and enhancing the compatibility of the support system.