煤矿巷道直墙半圆拱形波形钢腹板支架稳定承载性能

将新型波形钢腹板支架用于煤矿巷道金属支架结构中,采用试验研究和有限元数值模拟分析相结合的方法,研究波形钢腹板支架结构的稳定承载性能。设计了2榀直墙半圆拱形波形钢腹板支架的模型试验,得到支架的失稳破坏形态、应变与位移发展规律,并分析了波形钢腹板翼缘厚度变化对支架承载力的影响程度。结果表明:波形钢腹板支架破坏形态为整体非对称失稳,支架翼缘厚度由12 mm增加为16 mm时,即增幅为33%,支架的承载力提高27. 38%,表明翼缘厚度对支架的承载性能有显著影响。试验结果与有限元分析结果吻合良好,验证了有限元模型的正确性。同时采用有限元方法对用钢量基本相同的矿用工字钢支架和波形钢腹板支架进行对比,结果表明:波形钢腹板支架承载力比矿用工字钢提高了31. 68%,其变形约为矿用工字钢的4/5。通过数值模拟分析波形钢腹板支架截面各参数对支架弹性和弹塑性屈曲荷载的影响,发现腹板高度和厚度是较敏感参数;并比较了波形钢腹板支架和矿用工字钢支架分别在静水压力作用下、垂直单向应力作用下和垂向力为主的荷载作用下的支护性能,发现在相同的用钢量情况下,波形钢腹板支架具有较高的抗剪承载力,在高厚比很大的情况下不容易发生屈曲,且翼缘用钢量集中,使得截面的抗弯和轴压稳定承载力也大幅度提高,故它在各种荷载状态下的变形量均小于矿用工字钢支架,其支护效果优于矿用工字钢支架。

Stability behavior of support with corrugated steel webs of straight wall semicircle arch shape in coal mine roadway

A new type of metal support named H-Shaped members with corrugated webs was proposed to be applied in the metal support structure of the mine roadway.Through the experimental study combined with the finite element numerical simulation,the stability behaviors of this type of supporting structure with corrugated webs were studied.The model tests on two straight wall semicircle arch with corrugated webs were designed to obtain the failure mode,the strain and the displacement development rules of the support,and the influence of flange thickness of corrugated steel web on the supporting capacity is analyzed.The results showed that the failure mode of the corrugated steel webs was global asymmetric buckling,when the flange thickness of the corrugated steel webs was increased from 12 mm to 16 mm,increased by 33%,the bearing capacity of the support increased by 27.38%.It showed that the thickness of flange has a significant influence on the bearing capacity of the support.And the finite element model was verified by comparing the experimental results with finite element analysis.At the same time,the finite element method was used to compare the I-steel for mining with the corrugated web support with the same steel consumption.The results showed that the bearing capacity of the corrugated web support was 31.68% higher than I-steel for mining,and the deformation was about 4/5 of I-steel for mining.Through the numerical simulation of the influence of various parameters of the section of corrugated steel web support on the elastic and elasto-plastic buckling load of the support,it was found that the height and thickness of the web are more sensitive parameters.The supporting performance of the corrugated webs support and I-steel support for mining were respectively analyzed under the hydrostatic pressure,vertical unidirectional stress and vertical force.Results showed that with the same steel consumption,the corrugated web support had higher shearing capacity,and it was not easy to undergo buckling even if it had high height-to-thickness ratios.In addition,it was flexural and the axial stability capacity could also be greatly improved since the steel consumption was concentrated on the flanges.Therefore,the deformation of the corrugated web support was less than the mining I-steel support,and the supporting performance of the corrugated supporting was superior to I-steel support under various load conditions.