【作者】 邓涛；

【导师】 唐建新；

【作者基本信息】 重庆大学 ， 矿业工程， 2012， 博士

【摘要】 在煤矿开采活动中，瓦斯治理至关重要，而含瓦斯煤岩的渗透特性又是瓦斯治理的首要及关键问题，只有了解含瓦斯煤体的渗透特性才可以有针对性的进行瓦斯抽放，才能有效解决或缓解煤与瓦斯突出的危险。本文应用“含瓦斯煤岩三轴伺服渗流装置”，通过实验模拟原始应力场，研究了原煤在地应力场中的瓦斯渗流特性，对型煤试件进行了不含瓦斯以及含瓦斯条件下的卸围压试验。采用ABAQUS数值模拟软件，研究了上解放回采后，被解放煤层的应力场大小分布规律，结合现场实测的各项根据，分析了被解放煤层的卸压效果。取得的主要研究成果如下。①通过对轴向应力和围压的加、卸载，研究了软煤在地应力场中的瓦斯渗流特性，研究结果表明，软煤在加载过程中，其渗透率与有效应力之间的关系符合负指数函数关系，在卸载过程中，煤岩渗透率与有效应力间的关系符合幂函数关系，此外，通过反复的加卸载试验，结果表明，煤岩在经过2～3次循环后，其应变在以后的循环载荷过后变化很小，从渗透率来看，煤岩在经过前2～3次循环后，再进行循环加卸载，其渗透率几乎没有变化。②以原煤为研究对象，采用“含瓦斯煤热流固耦合三轴伺服渗流装置”对原煤渗透率的主要影响因素（轴压、围压和瓦斯压力）进行了试验研究，并拟合了煤岩渗透率与轴压（围压、瓦斯压力）的函数关系。③以型煤为研究对象，采用“含瓦斯煤热流固耦合三轴伺服渗流装置”进行含瓦斯煤岩的卸围压试验，研究煤岩在不同围压、不同初始轴向应力和不同卸围压速率的组合条件下，煤岩力学特性和瓦斯渗流特性，在该实验中，首先实验得到煤岩在不同围压条件下轴向应力-轴向应变的控制曲线，以此为基础，确定煤岩在不同围压条件下的屈服应力，从而确立卸围压试验中的卸围压开始时的初始轴向应力，对含瓦斯煤岩进行屈服前的卸围压试验，得到含瓦斯煤岩在不同围压、不同初始轴向应力及不同卸围压速率的组合条件下的力学及瓦斯渗流特性，总结出了含瓦斯煤岩在卸围压过程中，轴向应力平台与卸围压速率或初始轴向应力的关系，获得了含瓦斯煤岩的渗透率、应变、变形模量和泊松比在卸围压过程中的变化规律并采用多项式的形式拟合了煤岩渗透率与时间的关系。④采用“含瓦斯煤热流固耦合三轴伺服渗流装置”对型煤进行峰后卸围压的试验研究，针对不同围压条件下的型煤试件，采用位移加载方式，将试件的轴向应力加至峰值应力后，转为力控制，并保持轴向应力恒定后以一定的卸围压速率进行煤岩峰后卸围压试验，研究峰后卸围压条件下煤岩的力学和瓦斯渗流特性的规律，并与峰前卸围压试验的结果进行对比分析。⑤应用有限元软件ABAQUS，对上解放层回采后，被解放煤层应力场的大小及分布规律进行模拟分析，此外，通过对四川煤炭产业集团的白皎煤矿206区现场试验，现场观测上解放层回采过程中被解放煤层K1、K3的瓦斯压力、瓦斯含量及煤岩透气性系数，结合数值模拟的结果，分析了被解放层的卸压效果并确定了解放范围。更多还原

【Abstract】 In the underground coal mining activities， gas treatment is important，and thepermeability characteristic of coal containing gas is the principal and crucial problemin gas controling， only understanding permeability characteristics of coal containinggas，the gas drainage can be proceeded to solve or ease the dangerous of coal and gasoutburst，This paper applied“Thermo-fluid-solid coupling with triaxial servo-controlledseepage equipment of containing-gas coal”，researched the gas seepage characteristicsof raw coal in original stress field by simulating the stress field， mechanical and gasseepage characteristics is researched under different confining pressure、different initialaxial stress and different unloading speed of confining pressure，besides， by usingFLAC numerical simulation software，this paper researched the size and distribution ofstress field of liberated coal seam after the liberation coal seam is recovered， bycombinting the simulation and measured data，this paper analyzes the effect of releasingpressure.The main research results obtained as follows:①through loading and unloading the axial stress and confining pressure， gasseepage characteristics of soft coal under in-situ stress field is researched，the results ofthe study show that， in loading process， the relationship between permeabilityeffective stress tends to function relation，in unloading process， the relationshipbetween permeability effective stress tends to the power function relation， in addition，through repeated the loading and unloading， the experimental results show that after2~3times cycle， the strain changes very little， from permeability reaults， after theformer2~3times cycle， its permeability almost no change in another a loading andunloading cycle.②By using “Thermo-fluid-solid coupling with triaxial servo-controlled seepageequipment of containing-gas coal”，researched the main influence factors (axial stress，confining pressure and gas pressure)of raw coal permeability， and fitted the functionrelations.between permeability and the axial stress (confining pressure， the gaspressure)③By using “Thermo-fluid-solid coupling with triaxial servo-controlled seepageequipment of containing-gas coal”，proceeded experiment of unloading confiningpressure in the combination conditions of different confining pressure， different initial axial stress and different confining pressure unloading speed， obtained mechanicsproperties and gas seepage characteristics，in this experiment，first of all，axial stressand axial strain curve should be obtained in different confining pressure conditionsshould be obtained to get the yield stress of coal in different confining pressureconditions to establish the initial axial stress which is less than yield stress，byproceeding the tests of unloading confining pressure before yield stess，can get themechanics and gas seepage characteristics of coal containing gas under differentconfining pressure， different initial axial stress and different confining pressureunloading speed，then sums up the relationships between the time of axial stressplatform and confining pressure unloading speed or initial axial stress，obtain thechange rule of the permeability、strain、deformation modulus and poisson’s ratio in theprocess of unloading confining pressure，and fitted the function of permeability-time inthe form of polynomial.④Proceed the test of unloading confining pressure after the peak stress indifferent confining pressure，in the test，add the axial stress to the peak stress by thedisplacement loading method，turn to force control and maintain constant axial stressthen start to unloading the confining pressure after the peak stess，obtain the mechanicsand gas seepage characteristics of coal in the process of unloading confining pressureafter peak stress.⑤By using software ABAQUS numerical simulation， analyse the size and thedistribution rule of Stress field of liberated coal seam after the liberation layer is minedover. in addition， through the field test in206test field in baijiao coal mine of Sichuancoal industry group，combine the simulation results and the field observation results ofgas pressure、gas content and coal permeability in the process of mining liberationlayer，this paper analyse discharging pressure effect and determine the scope ofliberation.更多还原