极软岩巷道交岔点钢管混凝土支架结构设计与应用

为解决极软岩巷道交岔点支护问题,结合钢管混凝土支架和极软岩巷道围岩的力学特性,分析了钢管混凝土支架控制极软岩巷道变形的机理。对查干淖尔一号井井底车场中3个极软岩巷道交岔点支护问题采用了工程类比法进行分析,结果认为:若能充分发挥钢管混凝土的结构优势,采用"194 mm×10 mm钢管混凝土支架+钢筋网+400 mm厚混凝土喷层"的支护方案可有效控制3个极软岩巷道交岔点的围岩变形。因此,设计了适用于极软岩巷道交岔点的钢管混凝土支架结构形式:极软岩巷道交叉点钢管混凝土支架,采用由支撑架和"C"形异形支架组成的组合结构。提出了查干淖尔煤矿井底车场3个交岔点的支护方案,并进行现场支护试验。现场支护试验证明:巷道交岔点支护2 a后,收敛量小于100 mm,巷道稳定性良好。

Structural design and application of concrete-filled steel tube support at extremely soft rock roadway intersection

This paper aims to solve the ground support problem at the extremely soft rock roadway intersections.With the consideration of the mechanical property of extremely soft rock and concrete-filled steel tube (CFST) support，the mechanism of the deformation control in extremely soft rock roadway supported by CFST support is analyzed.The engineering analogy method is used to analyze the support problems at the extremely soft rock roadway intersections in Chagannoer NO.1 Coal Mine.The result shows that the problems can be solved by adopting the support with the 194 mm×10 mm CFST support，concrete spray and anchor net at the extremely soft rock roadway intersections，which can give a full play to the advantage of CFST support.Therefore，a design method of CFST structure，which is suitable for the extremely soft rock roadway intersection support，is put forward.The CFST combined structure used at the roadway intersection consists of support frame and “C” special shaped support.The support scheme based on CFST support is put forward to support three extremely soft rock roadway intersections.The field experiment results show that the amount of convergence of the roadway intersections is less than 100 mm.It proves that the CFST structure can be widely used in extremely soft rock roadways intersection support.