摘要
为了探讨冻结法井筒施工发生管涌事故的原因,以平煤一矿北三回风井为例,在混凝土井壁出现大量不规则而且宽度和深度较大的裂缝后,结合现场测试数据、地质条件和施工工艺对管涌事故进行了综合分析。由分析结果可知,管涌事故的主要原因为:1施工工艺不合理,如冻结管孔偏斜较大,注浆压力过大,混凝土浇筑不连续而出现施工冷缝,爆破装药量过大而引起的震动,致使混凝土在终凝前后就已产生载荷型裂缝;2混凝土配比、生产与养护不合理,如混凝土没有达到实际设计强度等级,无生产、浇筑养护措施,从而无法避免大体积混凝土的质量通病,即收缩裂缝;3地质条件的限制,如事故段岩石破碎,高角度裂隙发育,裂隙承压水压力大,构造应力大;同时,裂隙承压水与井壁外侧呈点接触或线接触,从而造成应力集中,发生横截面失稳现象。
In order to discuss the causes of water and soil gushing accident occurred in a ground freezing construction of a mine shaft,based on the North No. 3 Air Returning Shaft of Pingmei No. 1 Mine,after large abnormal and large width and depth cracks were appeared on the mine concrete liner,in combination with the site measured data,geological conditions and construction technology,a comprehensive analysis was conducted on the water and soil gushing accident. The analysis results showed that the major causes of the water and soil gushing accident were 1 the construction technology was irrational,such as the freezing pipe borehole was too deflection,the grouting pressure was too high,the concrete pouring was not continuous and the construction cold joints occurred,overcharging of the explosive loaded caused vibration and the concrete before and after the final setting would cause the loading cracks,2 the concrete mixing ratio,production and curing were irrational,such as the concrete could not reach the actual designed strength grade and no production and curing measures conducted,therefore large area concrete quality could not reach the designed requirements,such the shrinkage crack,3 the limitation of the geological condition,the rock at the accident section was broken,the high angle cracks were developed,the crack pressurized water pressure was too high and the structural stress was too high. Meanwhile the crack pressurized water were in a point connection or in a linear connection with the outside of the mine shaft and thus stress concentration occurred and the stability lost of the cross-section was occurred.
出处
《煤炭科学技术》
CAS
北大核心
2016年第3期26-32,共7页
Coal Science and Technology
基金
国家自然科学基金资助项目(41172317)
深部矿井建设省重点学科开放实验室开放基金资助项目(2011KF-01)
河南省教育厅科技攻关资助项目(2010A560010)
关键词
井筒
冻结法施工
大体积混凝土
裂缝
管涌
mine shaft
ground freezing construction
large volume concrete
cracks
water and soil gushing
