针对阳城煤矿-650南翼综机库(返修后为-650集中制冷硐室)底臌问题，采用现场调研和室内测试分析了底臌影响因素，包括断层破碎带影响、底板岩体质量差、底板浸水劣化和底板支护薄弱，其中前2条属于地质因素，要摸清参数分析利害，后两条属于人为因素，要优化设计设置防水。通过有限元模拟了原有支护和返修支护条件下底臌形成过程，模拟显示原支护条件下，巷道底板零位移标线距离巷道底板地坪7 m左右，零应变标线距离底板地坪10 m左右;底板有明显的3个区域:拉应变上升区、拉应变压缩区、压应变压缩区，其中拉应变上升区分布范围广且深度大(即零位移标线深度大)，围岩应力作用下拉应变上升区持续位移是造成底臌的关键原因。返修方案优化了全断面支护并重点强化底板支护力，模拟显示返修后底板零位移标线距离巷道底板地坪约4 m，与原有支护条件下相比，零位移标线抬升约3 m，减小了底臌发生区深度，控底效果显著。由此，提出了以底板零位移标线深度(即底臌产生区深度)来分析底臌作用机理，在单一变量条件下，分析得出底板支护力σ、底板岩体强度σc、巷道埋深H及巷道半径R与底板零位移标线深度hs的相关函数分别符合对数方程、幂函数、线性方程和对数方程。其中底板支护力和巷道半径影响作用显著，底板岩体强度影响作用次之，巷道埋深影响作用再次之。因此，为抑制底臌，在常规支护条件下应尽可能提高底板支护力;在巷道满足使用要求条件下应尽可能减小巷道尺寸;对软岩底板应尽可能保持或优化底板岩体强度，必须进行底板防排水。最后，实施了以锚网索喷+钢管混凝土支架技术优化全断面支护并以钢筋混凝土底梁强化底板支护的综合返修支护方案，工程实践表明返修后底臌控制良好，底臌量低于20 mm，计算钢筋混凝土底梁支护力1.02 MPa，钢管混凝土支架反底拱支护0.91 MPa，返修方案的底板总支护力σ=1.93 MPa，属于高支护力方案。但是返修方案也存在施工复杂和支护成本较高问题，为此提出由预制装配式弧板+控底锚索+防水层组成的优化支护系统，施工简单，成本经济。

In terms of the floor heave problem at -650 south wing fully mechanized chamber ( -650 centralized cooling chamber after repair) in Yangcheng coal mine,the influence factors of the floor heave were investigated by field inves- tigation and laboratory test,including the influence of fault fracture zone,the poor quality of floor rock mass,the deteri- oration of floor soaking and the weak support of the floor. Among them,the first two belong to geological factors. The second two belong to human factors. The optimized design and waterproofing should be considered. The formation process of floor heaves under the original support and rework support conditions was simulated by finite element meth- od. It was revealed that the zero displacement mark of roadway floor was about 7 m away from roadway floor and the zero strain mark was about 10 m away from roadway floor. There were three distinct areas in the floor:tensional strain increasing area,tensional strain sinking area and compressive strain sinking area,among which the tensional strain in- creasing area was widely distributed and into great deep area ( that is,the depth of the zero displacement marking), and the continuous displacement of tensional strain increasing area under surrounding rock stress was the key cause of floor heave. The rework scheme optimized the full section support and focused on strengthening the support force of the floor,which greatly increase the zero displacement marking. The simulation showed that the zero displacement mark of the floor after repairing was about 4 m away from the floor of the roadway. Compared with the original support condi- tion,the zero displacement mark increased about 3 m,which reduced the depth of the floor heave,and the effect of the bottom control was good. The mechanism of floor heave was analyzed with the depth of floor zero displacement marking (the depth of floor heave producing area). Under single variable conditions,the correlation function of floor support force,floor rock strength,roadway depth,roadway radius and zero displacement line depth were in accordance with log- arithmic function,power function,linear and logarithm function,respectively. Among them,the effect of floor support force and roadway radius was significant,the effect of floor rock mass strength was second,and the effect of roadway depth was weakest. Therefore,in order to restrain floor heave,the support force of floor should be increased as much as possible under the conventional support conditions;the size of roadway should be reduced as much as possible under the condition that the roadway met the production requirements;the strength of floor rock mass should be maintained or optimized as far as possible for the soft rock floor,and the floor waterproof and drainage must be carried out. Finally, the combined rework support scheme was put forward to optimize the whole section support with anchor net,cable spra- ying and concrete filled steel tube support technology,and reinforce the floor support with reinforced concrete bottom beam. The engineering practice showed that the floor heave was well controlled and the floor heave was less than 20 mm after the rework. The calculation results showed that the supporting force of reinforced concrete bottom beam was 1. 02 MPa,that of concrete filled steel tubular support was 0. 91 MPa,and that of the repairing scheme is 1． 93 MPa,which belongs to the high supporting force scheme. But the repaired support also was complicated in construction and high in cost. Therefore,an optimized support system composed of prefabricated arc plate,controlled bottom anchor cable and waterproof layer was proposed,which was simple in construction and low in cost.