摘要
Abstract
To comply with national environmental regulations,controlled blasting was used to demolish two chim-neys at a decommissioned coking plant in Bijie City.The twin chimneys exhibited identical material composition and dimensional specifications:each was a reinforced concrete structure with preserved external shells,incorporating re-fractory brick linings.Both structures measured 85 meters in height,with identical geometric parameters:a 7-meter outer diameter(21.98-meter circumference)at the base,featuring 36-cm-thick outer walls,24-cm-thick refractory linings,and a 4-cm insulating air gap between concentric layers.Situated in an urban setting with complex surround-ings,the chimneys were proximate to protected infrastructure,including industrial buildings,residential areas,and roadways(minimum clearance:60 meters).This required stringent mitigation of blast-induced hazards,particularly ground vibration and flyrock.Given that simultaneous detonation would produce excessive vibration,a sequential mil-lisecond-delay blasting technique with 110 ms inter-chimney delay was implemented.To minimize collapse-induced ground vibrations,four sand-soil cushion berms were strategically placed in the anticipated impact zones.Flyrock pre-vention was ensured by double-layer rubber-mesh reinforcement over the blast-cut sections.Computational analysis verified compliance with all safety standards for blast-induced hazards,including vibration and flyrock.Field observa-tions confirmed the chimneys achieved controlled diagonal collapse in opposite directions as planned.Vibration moni-toring at the closest protected structure registered 0.66 cm/s,well below the prescribed safety limit,while flyrock was effectively contained within designated boundaries.This successful demolition offers key technical benchmarks for similar engineering projects.关键词
钢筋混凝土烟囱/爆破拆除/对向错位/安全防护Key words
reinforced concrete chimney/blasting demolition/opposite staggered/safety protection分类
建筑与水利
