物理模拟试验可以直观展现底板突水全过程，并可获取采动底板突水灾变演化的多元化信息，成为研究承压水上开采的有效研究手段。对早期研制的深部采动底板突水模拟试验系统的突水流量监测、覆岩柔性加载、水平分级加载和恒压稳流试验舱等4个模块进行了改造，实现了突水水量区域化定量监测、覆岩柔性均布加载、双侧分区域独立加载、大容量恒压供水和全方位的密封等功能。借助改造后的试验系统和研制的非亲水相似模拟材料，以受底板承压水威胁的山东某矿为工程背景，研究了突水通道形成、流量灾变演化、隔水层应力变化等过程。试验结果表明：依据底板可视裂隙的扩展特征，将底板突水划分为横纵向演化阶段、横向周期演化阶段和灾变突水阶段；在第Ⅰ阶段，承压水顶界面主渗区首先产生于开切眼下方且位置不随煤层开采发生变化，随着开采可视裂隙向承压水含水层方向和工作面推进方向扩展，主渗区范围变大且流量显著提高；在第Ⅱ阶段，随煤层开采煤壁下方产生新的裂隙，上一轮回采产生的裂隙封闭，裂隙扩展呈现周期性变化特征，主渗区流量呈现降低—升高—降低—升高的周期性变化趋势；在第Ⅱ阶段，突水通道形成后，主渗区成为承压水突水的源头，其他区域流量不再发生突变，可将该阶段初期的流量急剧突变特征作为突水预警信息。试验结果不仅对中东部矿区承压水上开采底板突水溃砂过程中裂隙演化、突水流量特征研究提供实验指导，同时也对矿井安全性评价及灾害预测与防治提供参考。

Physical simulation test can directly show the whole process of mining floor water inrush,obtain diversified information of mining floor water inrush disaster,and has become an effective scientific research means to study the mining of confined water.In this paper,four modules of water inrush flow monitoring,flexible overburden loading,horizontal graded loading and constant pressure steady flow test module are modified which realizes regional quantitative monitoring of water inrush,flexible uniform stress distribution of similar materials in overburden,independent loading on both sides and sealing in all directions.Taking a coal mine in Shandong threatened by floor confined water as the engineering background,with the help of the up graded test system andnon hydrophilic similar simulation materials,the formation of water inrush channel,the evolution of flow disaster and the change of aquifuge stress are studied.The test results show that:according to the expansion characteristics of the floor visible fractures,the floor water inrush is divided into horizontal and vertical evolution stages,horizontal periodic evolution stages and catastrophic water inrush stages;In the first stage,the main seepage area of the confined water top interface first occurs under the open off cut,and the position does not change with the coal mining.With the expansion of the visible fractures to the confined water aquifer and the advancing direction,the scope of the main seepage area becomes larger and the flow rate increases significantly.In the second stage,with the formation of new fractures under the moving coal wall,the fractures produced by the previous mining cycle are closed,the fracture expansion presents periodic change characteristics,and the main seepage area flow presents a periodic change trend of decreasing,increasing,decreasing and increasing.In the second stage,after the formation of water inrush channel,the main seepage area becomes the source of confined water inrush,the flow rate of other areas is increased,and no mutation occurred in other areas.The sudden change of flow rate at the beginning of this stage can be used as early warning information of water inrush.The test results not only provide experimental guidance for the evolution of floor water inrush and the characteristics of water inrush flow in the process of mining above confined water in the middle and eastern mining areas,but also provide reference for mine safety evaluation,disaster prediction and prevention.

1 采动底板突水模拟试验系统升级

   1.1 传统底板突水模拟设备面临的问题

   1.2 改进的采动煤层底板突水模拟试验系统

2 煤矿矿底板承压水突水模型设计

   2.1 工程背景

   2.2 承压水突水模型设计

3 突水通道演化及数据监测结果分析

   3.1 隔水层突水通道演化过程

   3.2 底板区域涌水流量分布特征分析

   3.3 灾变瞬间流量变化特征及预警信息分析

   3.4 底板隔水层应力变化特征分析

4 结论