采矿与安全工程学报 ›› 2015, Vol. 32 ›› Issue (4): 617-622.

• 论文 • 上一篇    下一篇

厚松散层薄基岩充填开采覆岩裂隙发育分析

  

  1. 1.河南理工大学土木工程学院,河南 焦作 454003; 2.中国矿业大学深部岩土与地下工程国家重点实验室,江苏 徐州 221116
  • 收稿日期:2014-04-09 出版日期:2015-07-15 发布日期:2019-09-02
  • 作者简介:徐平(1981—),男,湖南省南县人,讲师,博士,从事采动岩体力学方面的研究。
  • 基金资助:

    国家自然科学基金项目(U1404527);国家重点基础研究发展计划(973)项目(2013CB227900);河南省科学技术研究重点项目 (14A560002,15A560007);河南省高校基本科研业务费专项项目(NSFRF140147)

Fracture development of overlying strata by backfill mining under thick alluvium and thin bedrock

  • Received:2014-04-09 Online:2015-07-15 Published:2019-09-02

摘要: 为分析厚松散层薄基岩固体充填开采覆岩裂隙发育规律,将厚松散层单一薄基岩视为作用在固体充填材料上的承载结构,建立了单层薄基岩Winkler 弹性地基连续梁力学分析模型;在力学分析基础上,得到了充填体压缩模量与岩梁任意截面裂隙发育高度的关系。通过分析固体充填材料压缩特性,建立了厚松散层单一薄基岩岩梁裂隙发育高度与充实率之间的对应关系。结合工程实例,在力学分析模型上采用UDEC 数值模拟软件建立数值模型,分析了充实率为60%,70% 和85%时岩梁裂隙发育情况,并与裂隙发育高度的经验公式预计值对比。研究表明:固体充填开采中由于充填体对上覆岩层的支撑作用,使得开采中上覆薄基岩塑性区发育高度得到抑制,从而限制了覆岩裂隙的发育;工作面推进过程中,其裂隙发育高度在工作面推进30~50 m 时迅速增长,且随着充实率的提高而迅速递减。分析及测试结果证实密实固体充填是确保松散含水层薄基岩下煤炭安全开采的有效途径。

关键词: 薄基岩, 充填开采, 充实率, 裂隙, 力学模型

Abstract: To analyze fracture development laws of overlying strata by solid backfill mining, by considering the thin bedrock under thick alluvium as a bearing structure above the solid filling materials, the model of Winkler elastic foundation continuous beam for the single thin bedrock was built, and the relation between the compression modulus of filling body and the fracture development height of single thin bedrock was obtained by the mechanical analysis. In addition, the correspondence between the fracture development height of single thin bedrock and the filling percentage were established by analyzing the compression characteristics of solid filling material. Combined with practical work, the UDEC numerical model based on mechanical analysis was further built, and the fracture developments of rock beam were analyzed with the filling percentages of 60%, 70% and 85% in solid backfill mining. The results show that the strata fracture development height can be inhibited by solid backfill mining duo to the supporting effect of filling body to the overlying strata during coal exploitation. Meanwhile, the strata fracture development height increases rapidly after the coal face moving forwards about 30 m to 50 m, and decreases rapidly with the increase of filling percentage. Thus, the solid dense backfilling is a safe and effective method in coal mining under the thick alluvium and thin bedrock.

Key words: thin bedrock, backfill mining, filling percentage, fracture, mechanical model