巷道格栅可缩性支架的力学分析

Mechanics analysis about the yieldable grid support of roadway

U型钢可缩性支架以支护能力大、可缩性和使用方便等特点,在难以支护的煤矿巷道中获得应用。但这种支架存在成本高、稳定性差和缩动条件苛刻等问题,限制其广泛使用。提出一种巷道格栅可缩性支架,通过力学计算,数值模拟分析和实验研究方法,研究了格栅可缩性支架的内力特征及在荷载作用下支架缩动产生的力学响应。结果表明,格栅可缩性支架结构合理,抗弯、抗扭性及稳定性能良好,支架承载能力大。支架缩动过程中,内力趋于均匀,缩动性质属于增阻型,而且缩动条件单一,在技术上容易控制,能保证支架在破坏前稳定地缩动,避免出现屈曲失稳而产生突发性破坏。这种支架质量轻、成本低、材料来源广、加工方便,而且便于与锚杆喷射混凝土联合支护,是一种有广泛应用前景的巷道支护形式。

The U-steel yieldable support is used in the coal roadway,which is difficult to be supported,due to its characteristics of high retaining ability,contractible capacity and convenient application. However,its own limitations of high cost,poor stability and harsh compressive conditions are difficult to be overcome,which results in its limited application.In order to solve these problems,a grille-yieldable support is proposed,and its internal force characteristic and the mechanical response caused by the yielding under the load are investigated through mechanical calculation,experimental research and numerical simulation analysis in this paper. The results show that this grille-yieldable support has a reasonable structure and a satisfactory performance on bending resistance and torsion resistance.Besides,its stability and bearing capacity are improved to a large extent.During the yielding of the support,the internal force tends to be uniform while the yielding resistance is gradually added.Due to the simplex yielding condition,it is ease to guarantee the support yielding steadily so as to avoid a sudden failure caused by buckling instability. The grille-yieldable support has many advantages such as light weight,low cost,abundant material source and easy manufacturing.In addition,it is convenient to operate with the bolt-shotcrete support,therefore,the grille-yieldable support is a practical roadway supporting form which has a great application prospect.