深圳地铁8号线岩溶发育特征及施工处理措施

摘要

In the exploration of Wangjihu stabling yard of Shenzhen Metro Line 8,it was found that there are marble interlayer in tuffolava and the development of karst.The karst caves developed in tuffolava are mainly controlled by weathering layer,fault structure and the spatial distribution of marble interlayer.Wangjihu stabling yard and the surrounding area generally belong to weakly developed karst area,but some local areas belong to strongly developed karst area.The cave sizes are small,the cave 0.80-12.0 m height,average 4.2 m.Karst is mainly developed in the marble interlayer between soil-like strongly and slightly weathered tuffolava.According to the cave sizes,properties of fillings and relationship between karst cave and tunnel,measures such as grouting reinforcement,applying umbrella arch and advanced pipe shed are adopted to ensure the construction quality of pile foundation,safety of tunnel construction and stability of stabling yard.%在深圳地铁8号线望基湖停车场及其出入线的勘探中,发现凝灰熔岩中存在层状或透镜体状的大理岩夹层,且岩溶现象发育,在凝灰熔岩中的溶洞主要受控于大理岩夹层的空间分布形态、风化层位及断裂构造.望基湖停车场及附近场地总体属岩溶弱发育地段,但局部地段属岩溶强发育地段,溶(土)洞规模较小,洞高0.80 ～12.0 m,平均4.2m,主要发育在土状强风化—微风化凝灰熔岩之间的大理岩夹层中.根据溶(土)洞规模大小、充填物性质及与隧道的位置关系,采取注浆加固、施做套拱和超前大管棚等措施,确保了桩基施工质量、隧道施工安全和停车场场坪的稳定性.