后压浆技术在石家庄隧道钻孔灌注桩中的应用

钻孔灌注桩的后压浆技术在桥涵和房屋建筑中应用很多,但注浆工艺、注浆参数对岩土的适用性都有待进一步研究.京石客专石家庄隧道的盖挖段施工中由于地质原因灌注桩达不到设计桩长,采用成桩后对支撑桩进行后注浆处理的措施,以提高支撑桩的单桩承载力.介绍了钻孔灌注桩后注浆的作用机理,进行了注浆前与注浆后桩基承载力的对比计算,阐述了具体...

Application of the Post-grouting Technique to Bored Piles of the Shijiazhuang Tunnel

Although the post-grouting technique for bored piles has been widely used in the construction of bridges,culverts and buildings,the adaptability of the grouting process and the grouting parameters to the geotechnical conditions still needs to be further studied.During the construction of the cut-and-cover section of the Shijiazhuang Tunnel of the Beijing-Shijiazhuang Passengers-oriented Railway,the bored piles fail to reach the designed lengths due to the geological conditions,in which case the post-grouting is executed for the completed bored piles so as to improve the load-bearing capacity of each of the piles.The working mechanism of the post-grouting for bored piles is presented in the paper,with a comparison between the load-bearing capacity of the bored piles before being post-grouted and that after being post-grouted made,and the specific post-grouting process described.The static loading tests on the single bored pile show that the load-bearing capacity of the single pile is up to the relevant requirements.