Vol.28 No.9 尹尚先等：陷落柱概化模式及突水力学判据 ·817。 Generalized modes and academic criterions of water inrush from paleo-sinkholes Y IN Shangxian.WU Qiang? 1)Safety Engineerin Center.North China Institute of Science and Technology.Beijing 101601.Chima 2)Faculty of Resouroes and Safety Engineering,China University of Mining and Technology Beijing 100083 China ABSTRACT According to locational relat ions betw een a paleo-sinkhole and a working face or tunnel the modes of paleo-sinkhole-caused water inrush (hereinafter referred to as water inrush from paleo-sinkholes) are divided into the mode of water inrush from roof/floor and the mode from rib as well as four sub-modes including the thin plate sub-mode of water inrush,the shear failure sub-mode,the thick wall cylinder sub- mode and the hydro-fracture sub-mode.The thin plate sub-mode is applicable to the circum stance where the key layer of cylinder cover is complete and has small thickness,and its criterion of water inmush is the limit bending moment.The shear failure sub-mode is applicable to the circumstance where the key lay er of cy lin- der cover has big thickness,and its criterion of water innush is a quadratic parabola equation.In the thick wall cylinder water inrush mode,the elastic limit pressures that may lead to failure of the thick wall cy lin- der are different as the different yield empirical rules but all are in direct proportion with the strength of rock stratum.The hydro-fracture sub-mode of w ater inrush describes the type of water inrush that occurs due to the interconnection between underground water and other inherent structures through hydro-fracture when the paleo-sinkhole is far from the working face or tunnel.The critical hy dro-fracture pressure may be calculated by reference to the formula used for calculating hydro-fracture.It is indicated by an actual exam- ple that the water inrush modes and their criteria are simple and feasible conform to the realities and have sufficient accuracy. KEY WORDS mining engineering;paleo-sinkhole;water inrush mode;thin plate theory;thick wall cylinder;shear failure;hydro-fracture;academic criterion (上接第811页) Particle flow analysis on mechanized top-coal caving in steep thick seam WANG Shuren'.2》,WANG.Jinan2》,LIU Shuhong》,WU Shunchuan2》,XIE Junwen2》 1)School of Civil Engineering and Mechanics Yanshan University,Qinhuangdao 066004.China 2)Civil and Envimonmental Engineering School Uriversity of Science and Techmlogy Beiing.Beijing 100083 Chima 3)Notheastem University at Qinhuangdao.Qinhuargdao 066004 China ABSTRACT By using PFC2Dtechnique the falling and moving process of top-coal and rock,and the flow- ing characteristics of loose medium in the process of top-coal caving in steep thick seam were analyzed for the horizontal and inclining compound working face arrangement of a coal mine by different recovering dis- tances.The recovery of top-coal and the force characteristics of the powered supports for the top-coal caving working face by different caving sequences were discussed.The results showed that,firstly,the recovery of top-coal was high and the force characteristic of the powered supports for top-coal caving was good by adopting the top-to-dow n caving sequence.Secondly,the falling and moving configurat ion of loose medium w as deflected tow ard the mined direction.Thirdly,the characteristic of lost coal in the process of top-coal caving was present with a particular rhythm.At last,the optimal caving distance w as 1.2 m in all the con- ditions. KEY WORDS steep thick seam;mechanized top-coal caving:loose medium;movement character;nu- merical simulationGeneralized modes and academic criterions of water inrush from paleo-sinkholes Y IN Shangxian 1), WU Qiang 2) 1)Safet y Engineering Cent er , North China Institut e of S cience and Technology , Beijing 101601 , C hina 2)Faculty of Resources and S afety Engineering , China University of Mining and Technology, Beijing 100083 , China ABSTRACT According to locational relations betw een a paleo-sinkhole and a w orking face or tunnel, the modes of paleo-sinkhole-caused w ater inrush (hereinafter referred to as w ater inrush from paleo-sinkholes) are divided into the mode of water inrush from roof/ floor and the mode from rib as w ell as four sub-modes, including the thin plate sub-mode of w ater inrush , the shear failure sub-mode , the thick wall cylinder sub￾mode and the hydro-fracture sub-mode .The thin plate sub-mode is applicable to the circumstance w here the key layer of cylinder cover is complete and has small thickness, and its criterion of w ater inrush is the limit bending moment .The shear failure sub-mode is applicable to the circumstance w here the key lay er of cy lin￾der cover has big thickness, and its criterion of w ater inrush is a quadratic parabola equation .In the thick w all cylinder water inrush mode , the elastic limit pressures that may lead to failure of the thick w all cy lin￾der are different as the different yield empirical rules, but all are in direct propo rtion w ith the streng th of rock stratum .The hydro-fracture sub-mode of w ater inrush describes the type of w ater inrush that occurs due to the interconnection between underg round w ater and other inherent structures through hydro-fracture w hen the paleo-sinkhole is far from the working face o r tunnel.The critical hy dro-fracture pressure may be calculated by reference to the formula used for calculating hydro-fracture .It isindicated by an actual exam￾ple that the water inrush modes and their criteria are simple and feasible , conform to the realities and have sufficient accuracy . KEY WORDS mining engineering ;paleo-sinkhole ;w ater inrush mode ;thin plate theory ;thick w all cylinder;shear failure;hydro-fracture;academic criterion (上接第 811 页) Particle flow analysis on mechanized top-coal caving in steep thick seam WANG Shuren 1 , 2), WANG J inan 2), LIU S huhong 3), WU Shunchuan 2), X IE Junwen 2) 1)School of Civil Engineering and Mechanics, Yanshan University , Qinhuangdao 066004 , China 2)Civil and Environment al Engineering S chool, Uni versit y of Science and Tech nology Beijing , Beijing 100083 , C hina 3)Northeastern University at Qinhuangdao , Qinhuangdao 066004 , China ABSTRACT By using PFC 2D technique , the falling and moving process of top-coal and rock , and the flow￾ing characteristics of loose medium in the process of top-coal caving in steep thick seam w ere analyzed for the horizontal and inclining compound wo rking face arrangement of a coal mine by different recovering dis￾tances .The recovery of top-coal and the force characteristics of the powered supports for the top-coal caving w orking face by different caving sequences were discussed .The resultsshowed that , firstly , the recovery of top-coal w as high and the fo rce characteristic of the powered supports for top-coal caving w as good by adopting the top-to-dow n caving sequence.Secondly , the falling and moving configuration of loose medium w as deflected tow ard the mined direction .Thirdly , the characteristic of lost coal in the process of top-coal caving was present with a particular rhythm .At last , the optimal caving distance w as 1 .2 m in all the con￾ditions . KEY WORDS steep thick seam ;mechanized top-coal caving ;loose medium ;movement character;nu￾merical simulation Vol.28 No.9 尹尚先等:陷落柱概化模式及突水力学判据 · 817 ·