“钟”形采空硐室结构特征参数分析

摘要

According to the long-term mining experience,the ancient quarrymen quarry rocks to form the bellshape caverns without any pillar.Because the north-south and southwest-northeast gradients are different,the caverns have different cross-sections.So the bottom of caverns is approximately oval.This paper explores the scientific rules of structural features of the bell-shape caverns of Huaxuan caverns and Huaju caverns in Changyu,Wenlin,Zhejiang province,and the scientific rules of structural features.It examines the characteristics of the structure parameters of bell-shape caverns for further analysis of the influence factors of the large cavern group.The topographic slope,the span-high radio and the buried depth and height ratio of cavern are analyzed with the FLAC for analyzing the structure parameter character of the bell-shape caverns.Analysis of the stress and plastic zone shows the following results.For the gentle slope surface,the span-high radio is less than 1.44 and the height ratio is less than 1.8.For the steep slope surfacedirection,the span-high radio is less than 1.28 and the height ratio is less than 1.8.About 67.7％ of the 24 caverns can meet these rules.So,the reasonable structure character of the bell-shape cavern has resulted them to have been stability for one thousand years.%古人根据长期采矿经验,在长屿硐天矿区开挖形成了无柱式“钟”形硐室,并根据NS走向和SW-NE走向地形坡度不同的情况,采用不同的断面跨度,导致硐室底部呈近似椭圆形.为深入探寻长屿硐天华玄硐群与花居硐群“钟”形硐室结构特征的科学规律,深入总结古人工程技术经验,进一步分析大型硐室群屹立千年不倒的影响因素,本文深入开展“钟”形采空硐室结构参数特征的研究,以地形坡度、硐室跨高比、硐室埋深与高度比为因素,采用FLAC进行数值模拟计算,对硐室围岩的应力以及塑性区进行了深入分析,得出了结论为:在缓坡方向,硐室跨高比宜小于1.44,硐室埋深与硐高比宜小于1.8;在陡坡方向,跨高比宜小于1.28,硐室埋深与硐高比宜小于1.8.勘查的24个硐室中有67.7％硐室符合该规律,可见古人采用了较为合理的“钟”形硐室结构形式,为洞室千年稳定奠定了良好基础.