为了防止华北型煤田下组煤开采因围岩破坏致煤层底板奥灰突水,基于FLAC3D数值模拟软件,建立了下组煤开采试验工作面数值模型,利用光纤光栅传感器技术,监测了工作面回采过程中底板突水信息,通过数值模拟与监测结果的对比,获得了工作面煤层顶底板应力与破坏特征。结果表明:试验工作面初次来压步距为35～40 m,周期来压步距为10～20 m;工作面底板存有3个应力分区,即应力增高区、应力降低区和应力恢复区;煤层顶板破坏形态为沿走向和沿倾向方向"马鞍形"的叠加;试验工作面煤层底板破坏深度10.0～12.5 m,开切眼与终采线位置附近煤层底板破坏深度均达22.5 m,终采线位置附近煤层底板破坏深度大是试验工作面突水的主要原因。

In order to prevent coal mine water hazards results from surrounding rock failure by mining lower coal in North China Coalfield, a numerical model was b uilt based on the numerical simulation software FLAC3D.Water inrush information was monitored during mining process based on the optical fiber grating sensor techno logy.Lower coal surrounding rock stress and failore rules were studied by comparing numerical simulation and monitoring results.This research showed that the first wei ghting distance of the test face was from 35 m to 40 m and the periodic weighting step distance was from 10 m to 20 m.The coal floor could be divided to three stress ar eas which was increased stress zone, decreased stress zone and recovery stress zone.The coal roof failure shape was a composition of two saddle-shaped zones alon g trend and tendency directions.Normal failure depth of test face coal floor was from 10 m to 12.5 m, and it could reach 22.5 m near open-off cut and stop line.The large failure depth near the final line was the main reason of the test face water inrush accident.

国家自然科学基金重点资助项目(51034003)；中国煤炭科工集团西安研究院技术创新基金资助项目(2011XAYCX011)；“十二五”国家科技支撑计划资助项目(2012BAC10B03)；