摘要
钻孔灌注桩后压浆技术,使水泥浆液在高压下渗透、充填和挤密,与沉渣、泥皮、桩周和桩端土体发生物理化学固结,增大了土体和桩端的强度,改变了桩的受力类型,提高了桩侧摩阻力和端阻力,从而提高了单桩的承载力。在苏通大桥超长大直径桩中应用了桩底后压浆技术。通过试桩静载试验,决定在工程施工中采用U型压浆管方案。试桩结果表明,压浆后极限承载力测试值是压浆前的1.48～2.0倍,压浆后端阻力是压浆前的2.46～7.21倍,表明利用后压浆技术达到了节约工程投资、提高工程施工质量及可靠性的目的,并产生了较大的技术经济效益和良好的社会环境效益,这将促进我国公路桥梁建设的桩基技术迈向一个新台阶。
Post-grouting technique has a wide range application to piled foundations.The principle of post-grouting technique is as follows： through grouting cement into bottom of bored pile or around pile body,the loose material such as deposit and slime during pile construction can be strengthened;and it can highly increase frictional resistance and end bearing capacity of pile.Post-grouting technique was successfully employed in the piled foundation of Su-Tong Bridge,a huge bridge under construction which connects Suzhou City and Nantong City in Jiangsu Province,China.According to the results of static load tests,the U-shape grouting pipe was used in the project for the piles’ bottom grouting.After grouted,values of the ultimate bearing capacity of the tested piles were increased up to1.48-2.0 times the ones of un-grouted bored piles.For end bearing capacities,their values were increased up to 2.46-7.21 times.It can be drawn a conclusion that through using post-grouting technique,it saves investment,improves construction quality and reliability,and brings considerable economic benefits and well social environment effects as well.
出处
《岩土力学》
EI
CSCD
北大核心
2008年第6期1697-1700,共4页
Rock and Soil Mechanics
