为研究由装配整体式高延性混凝土(HDC)、带肋叠合板(PK板)、冷弯薄壁型钢组成的T型肋叠合楼板(HTPKG板)底板受力性能,通过HTPKG预制底板试件的重物均布加载静载试验,研究了HTPKG板的刚度、承载力等力学性能。分析跨度、上翼缘宽度、腹...为研究由装配整体式高延性混凝土(HDC)、带肋叠合板(PK板)、冷弯薄壁型钢组成的T型肋叠合楼板(HTPKG板)底板受力性能,通过HTPKG预制底板试件的重物均布加载静载试验,研究了HTPKG板的刚度、承载力等力学性能。分析跨度、上翼缘宽度、腹板宽度等因素对HTPKG板受压性能和承载力影响规律,选出最优板型。试验结果表明:在加载至4.4~4.5 k N时板底跨中位置均出现了裂缝,极限荷载下未出现脆断现象,说明HTPKG板具有较好的承载力和延性特征,HTPKG-4板的受力性能最佳。展开更多
The variation in bedding thickness of the weak immediate floor has long been a challenge in the lllinois basin coal mines when it comes to floor stability. The vertical thickness of the immediate floor is not constant...The variation in bedding thickness of the weak immediate floor has long been a challenge in the lllinois basin coal mines when it comes to floor stability. The vertical thickness of the immediate floor is not constant throughout the mines and can vary over short horizontal distances. The biggest misconception from a design standpoint is to use the maximum or average thickness found from core logs taken from various locations on the mine property. The result of this practice is oversized pillars in the areas where the weak immediate floor has thinned vertically. This over-design leaves coal in situ which could have otherwise been extracted. This paper presents a plane strain numerical model to illustrate the effect of a change in bedding thickness of a weak immediate floor across one or two coal pillars. The floor bearing capacity of the variable floor below each pillar where then compared to the consistent floor. The results show that the varying bedding thickness of weak underclay has an impact on the bearing capacity of the floor. Geometrically with the decrease in bedding thickness for constant pillar width, the B/H ratio increases exponentially. The influence of varying bedding thickness on the floor bearing capacity is apparent at higher B/H ratios. The floor bearing capacity under a single pillar is in variable floor model if the average thickness remains constant. For single pillar, the average of the bedding thickness can be considered and for pillars in a panel, and a safety factor has been proposed to take into account this change in bedding thickness.展开更多
文摘为研究由装配整体式高延性混凝土(HDC)、带肋叠合板(PK板)、冷弯薄壁型钢组成的T型肋叠合楼板(HTPKG板)底板受力性能,通过HTPKG预制底板试件的重物均布加载静载试验,研究了HTPKG板的刚度、承载力等力学性能。分析跨度、上翼缘宽度、腹板宽度等因素对HTPKG板受压性能和承载力影响规律,选出最优板型。试验结果表明:在加载至4.4~4.5 k N时板底跨中位置均出现了裂缝,极限荷载下未出现脆断现象,说明HTPKG板具有较好的承载力和延性特征,HTPKG-4板的受力性能最佳。
文摘The variation in bedding thickness of the weak immediate floor has long been a challenge in the lllinois basin coal mines when it comes to floor stability. The vertical thickness of the immediate floor is not constant throughout the mines and can vary over short horizontal distances. The biggest misconception from a design standpoint is to use the maximum or average thickness found from core logs taken from various locations on the mine property. The result of this practice is oversized pillars in the areas where the weak immediate floor has thinned vertically. This over-design leaves coal in situ which could have otherwise been extracted. This paper presents a plane strain numerical model to illustrate the effect of a change in bedding thickness of a weak immediate floor across one or two coal pillars. The floor bearing capacity of the variable floor below each pillar where then compared to the consistent floor. The results show that the varying bedding thickness of weak underclay has an impact on the bearing capacity of the floor. Geometrically with the decrease in bedding thickness for constant pillar width, the B/H ratio increases exponentially. The influence of varying bedding thickness on the floor bearing capacity is apparent at higher B/H ratios. The floor bearing capacity under a single pillar is in variable floor model if the average thickness remains constant. For single pillar, the average of the bedding thickness can be considered and for pillars in a panel, and a safety factor has been proposed to take into account this change in bedding thickness.
