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基于体积应变的煤体渗透率模型及影响参数分析 被引量:4
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作者 王伟 余金昊 +4 位作者 方志明 李小春 李琦 陈向军 王亮 《煤炭学报》 EI CAS CSCD 北大核心 2024年第6期2741-2756,共16页
为研究瓦斯压力变化过程中渗透率演化规律,基于煤体代表性单元体(REV)细观尺度参数与体积应变关联特征推导了4种不同形式渗透率模型。利用实验数据对模型进行了可靠性验证,分析了有效应力引起的应变和吸附应变的变化规律,并与经典渗透... 为研究瓦斯压力变化过程中渗透率演化规律,基于煤体代表性单元体(REV)细观尺度参数与体积应变关联特征推导了4种不同形式渗透率模型。利用实验数据对模型进行了可靠性验证,分析了有效应力引起的应变和吸附应变的变化规律,并与经典渗透率模型(P-M模型、S-D模型、CONNELL模型)进行对比验证。讨论了模型参数的敏感性,明确了REV细观尺度参数与裂隙率、渗透率的相关关系,并分析了吸附应变系数影响机理,进而对国内主要矿井渗透率极值压力进行了研究。结果表明:基于REV体积应变与REV裂隙体积应变的4种渗透率模型,其REV体积应变与REV裂隙体积应变线性相关,相关系数为初始裂隙率;体积模量与吸附应变系数分别控制有效应力和吸附应变对渗透率的影响;恒定围压、恒定孔压、恒定差压3种实验条件下,相比经典渗透率模型,4种渗透率模型对实验数据都有较好的匹配效果,但双参数拟合(体积模量与吸附应变系数)相比单参数拟合(吸附应变系数),参数的拟合误差较大,由参数敏感性分析可知,当参数变化时(<10%)渗透率预测结果相比真实值也有较大偏差;以沁水盆地为例,计算的煤体REV细观尺度参数a_(0)、b_(0)范围分别为1.73~46.31μm和0.06~0.49μm;恒定围压与恒定差压条件下,吸附应变系数与差压大小、气体类型及初始裂隙率有关;国内主要矿井CO_(2)极值压力在0.94~5.33 MPa,CH4极值压力在1.06~6.94 MPa。 展开更多
关键词 渗透率 表征单元体 多实验条件模型 参数敏感性 吸附应变系数
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Structural behaviors of steel roof truss exposed to pool fire 被引量:1
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作者 陈长坤 张威 《Journal of Central South University》 SCIE EI CAS 2012年第7期2054-2060,共7页
Experimental research was conducted to study the structural behaviors of a steel roof truss model without fire-proof coating under pool fire conditions. The data of temperature distribution and displacements of typica... Experimental research was conducted to study the structural behaviors of a steel roof truss model without fire-proof coating under pool fire conditions. The data of temperature distribution and displacements of typical members were obtained. It is found that the temperature distribution of environment inside the structure, which is found to be in accordance with the multi-zone model with height, has a decisive effect on the tempera^tre evolution of steel members. Besides, it can also be observed that due to the restriction and coordination among the truss members in the localized fire, the maximum relative deflection, which occurs at the mid-span of the top chord, is relatively slight and has not exceeded 1 mm under experimental conditions. On the other hand, the column experiences a notable thermal expansion during the test. Then, a finite element model is presented and validated by the test results. 展开更多
关键词 steel roof truss fire test multi-zone model finite element analysis
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