深部充填开采留巷球应力壳与偏应力场演化及协同控制

For the complicated environment of deep gob-side retaining entries’ surrounding rock, mechanical response relationship between surrounding rock behavior and rock environment will be analyzed, and furthermore, based on the relevance between spherical stress and each principal stress, the forming and distribution feature of three-dimensional spherical stress shell influenced immediately by deep gob-side retaining entries disturbing action will be studied as well. And then, the controlling effect of spherical stress shell to overlying strata behavior and the protecting mechanism to lower retaining entries will be illustrated. The relationship between zonal rupture forms of coal-rock covered by the shell and spherical stress subsidence in deep retaining entries will be researched. In addition, space-time evolution law of deviator stress filed and accumulation and dissipation of surrounding rock distortion energy will be investigated as well, and then the principle control mechanism of such evolution law to deep surrounding rock distortion will be demonstrated. Collaborative support structural model consists of non-uniform loaded filling body, roadside support and weak-structured coal sides will be established, in addition, the collaborative control mechanism of integral backfilling in gob, road-side and road-in support of deep retaining entries will be revealed. Besides, reaction mechanism of gob filling to spherical stress shell and the weaken effect to coal-rock zonal rupturing process will be investigated, and so will be the stability maintenance and compensation effect to weak interface of road-in support. Furthermore, the key collaborative control technique of deep retaining entries and its parameter optimization methods will be proposed, which will provide key theoretical and technical support for stability control of surrounding rock in deep retaining entries.

针对深部充填开采沿空留巷围岩所处的复杂特殊环境，分析其覆岩体活动特征及其与岩体环境的力学响应关系，进而基于球应力与各主应力之间的关系，研究深部充填开采留巷扰动围岩三维球应力壳形成与分布特征，揭示球应力壳对覆岩体活动的控制作用和下部留巷工程的保护机制。探讨深部留巷球应力壳下煤岩体分区破裂形式及其与球应力壳下沉的关系，研究球应力壳下偏应力场、围岩畸变能积累与耗散的时空演化规律，阐明其对深部留巷围岩畸变的主控作用。建立非均布受载充填体、巷旁支架与弱结构煤帮协同支撑的围岩结构模型，揭示采空区整体充填、巷旁和巷内支护对深部留巷围岩协同控制作用机理。探究采空区充填对球应力壳反作用机理和围岩分区破裂的弱化作用机制以及巷内支护对围岩的维稳和弱面补偿作用，形成深部充填开采沿空留巷围岩协同控制技术关键与参数优化方法，为深部留巷围岩稳定性控制提供关键理论和技术保障。

针对深部充填开采采场与留巷围岩所处的复杂特殊环境，以邢东矿深部充填工作面为工程背景，采用理论分析、实验室试验、数值模拟和现场工程试验，分析采场和留巷围岩偏应力、塑性区和球应力时空演化规律，研究充填留巷覆岩活动特征和留巷围岩控制原理和方法。取得了如下主要创新成果：① 沿煤层走向，采场围岩偏应力分布演化形态为扁平小椭圆状→扁平大椭圆状→上端开口椭圆状→对称扇形拱，且偏应力峰值带以工作面周围→工作面底部和两侧→工作面两侧进行转移。沿煤层倾向，偏应力峰值带以采空区顶底板→工作面顶底部、煤壁前方和开切眼前方顶部进行转移；② 沿煤层走向，采场围岩塑性区分布演化形态为椭圆状。沿煤层倾向，采场围岩塑性区分布演化形态为近似圆状→近似长葫芦状；③ 沿煤层走向和煤层倾向，采场覆岩均被球应力过渡带划分为6个区域，球应力过渡带位于覆岩弯曲下沉带中，其将采场覆岩中未破坏岩体形似“托举”起来，对下部采场活动起到“保护作用”；④ 充填体C2（水灰比5:1）较充填体C1（水灰比6:1）更能适应深部矿井复杂力学环境；⑤ 随工作面推进，巷道围岩球应力峰值由顶底板逐渐转移至实体煤帮，球应力分布形态由花瓣状逐渐演化为被球应力过渡带划分成的类双曲线形态，球应力过渡带可看成留巷围岩中未破坏岩体的“骨架”，未破坏岩体形似被这个“骨架”支撑起来，对留巷围岩起到“保护作用”；塑性区分布形态以近似椭圆状→近似圆状→半球状进行演化，且塑性区呈非对称分布，球应力过渡带弹塑性交界面区域；⑥ 充填留巷围岩球应力时空演化因素的主次顺序为采深>充填高度>侧压系数>采高；⑦ 偏应力分布形态以瘦高椭圆状→近似圆状→小半圆拱→大半圆拱→扇形拱进行演化，偏应力峰值带以顶底板→顶底帮角（实体煤侧）和实体煤帮进行转移，偏应力峰值带位于弹塑性交界面区域，充填留巷围岩偏应力时空演化因素的主次顺序为采深>充填高度>采高>侧压系数；⑧ 建立非均布受载充填体、巷旁支架与弱结构煤帮协同支撑的围岩结构模型，得到了留巷围岩剪应力分布特征；⑨ 基于深部充填开采留巷围岩球应力、偏应力和塑性区非对称分布特征，提出了分区非对称围岩控制技术，形成了深部充填开采沿空留巷围岩协同控制技术。