国内学者对浅埋煤层开采引起的上部松散含水沙层溃入采场的研究十分深入，泥沙来源于第四系松散层已成为共识。近年来西北侏罗纪巨厚基岩下采煤引起的水-砂混合突涌事故日益增多，成为一种新的危害性较大的地质灾害，目前国内学者对此鲜有研究。为揭示基岩突水溃沙的孕灾机理，制定科学的防范措施，以陕西黄陇煤田某矿采煤工作面突水溃沙事故为例，首先对前人做出的事故原因分析和认定提出技术商榷和探讨;依据补充勘探成果，结合突水溃沙过程，提出该起事故具有离层水害特征:离层空间汇集水源功能将砂岩裂隙水转化为“自由”水体，引起短时高强度突水，进而提出离层水害需要同时具备5个条件，即岩石力学条件、富水性(水源)条件、汇水时间条件、离层空间条件、导水通道条件等。其次，根据大量的岩石物理力学试验数据，判断4-2煤层上覆岩层具备离层产生的物质基础;根据离层水害时间、空间条件，借用“经验公式”推断引起该起事故的离层空间应该位于4-2煤顶板上30.54～77.10 m的地层内，并将这个高度范围内的地层作为富水性评价的目标层段;选取砂岩层厚度、脆塑性比值、构造分维等3种地学信息，采用新型复合叠加方法，绘制了富水性综合指数等值线图，事故点位于相对富水区内，证明离层空间所处的围岩具备离层水害的富水性(水源)条件;室内对现场采集的砂岩做了吸水崩解性试验，试验表明4-2煤层上覆砂岩遇水极易崩解，在水动力下具有显著的流沙属性，结合历次勘探没有发现到古河床(或称松散地质体)这一事实，分析该起事故的泥沙来源于含水基岩。最后，依据离层水害发生必须具备的5个基本条件，提出改变地层富水性条件或破坏离层空间封闭性条件(或汇水时间条件)等源头治理的技术措施。通过对本起典型案例的研究，揭示了西北侏罗纪煤田基岩下突水溃沙的孕灾机理，强调事故偶发性，对西部条件类似矿区煤炭资源安全开采具有一定的借鉴作用。

Some scholars have made lots of indepth researches on the inrush of the upper loose waterbearing sand layer caused by shallow coal mining.It is well known that the sediment originates from the quaternary loose layer.In recent years,the mixed watersand outburst accidents caused by mining coal under Jurassic Thick Overburden Rock in northwest China are increasing,which has become a new and harmful geological harzard.In order to reveal the mechanism of watersand inrush in bedrock and to find some scientific preventive measures,taking the accident in the coal mining face of Huanglong Coalfield in Shaanxi Province as an example,based on the supplementary exploration results and combined with the accident process,this paper puts forward a technical discussion on the cause analysis and determination of the accident made by predecessors.It points out that this accident has the characteristics of separated layer water disaster:the function of collecting water source in separated layer space transforms the sandstone fissure water into “free” water body,which causes shortterm and highintensity water inrush,and then it also points out that the separated layer water disaster needs five conditions simultaneously,namely,rock mechanics,waterrichness,time,space and channel conditions.Based on a large number of experimental data of rock physics and mechanics,it is concluded that the overlying strata of 4-2 coal seam have the material basis of separation formation,and according to the time and space conditions,combined with the application the “Empirical Formula”,it is concluded that the separation space causing the accident should be located in the stratum range of 30.54-77.10 m above the 4-2 coal roof,and the stratum in this height range should be taken as the target stratum for waterrich evaluation.Sandstone thickness,brittleplastic ratio and structural fractal dimension are selected,and a new composite superposition method is used to draw the isogram of waterrich comprehensive index.It is proved that the surrounding rock has the waterrich (water source) condition,considering the fact that the ancient riverbed (or loose geological body) has not been found in previous exploration,and the sediment in this accident originates from waterbearing bedrock.Finally,according to the five basic conditions,some technical measures are put forward to change the formation waterrich condition or to destroy the closure condition (or time condition).Through the study of this typical case,revealing the disasterinducing mechanism of watersand burst in mining under thick overburden bedrock of Jurassic Coalfield in northwest China,it can be used for the safe mining at similar mining area in the west of China.

1 概况

    1.1 地质条件

    1.2 突水溃砂过程

2 事故分析与技术探讨

    2.1 事故原因分析

    2.2 技术商榷

3 事故原因再分析

    3.1 离层水害发生条件

    3.2 离层裂隙产生的物质基础

    3.3 离层空间位置

    3.4 水源（富水性）条件

    3.5 泥砂来源

    3.6 偶发性特点

4 防治措施

5 结论