双护筒技术在大直径灌注桩静载试验中的应用研究

Application of Double Casing Technology in Static Load Test of Large Diameter Cast-in-situ Piles

通常,在地面实施静载试验,而对于有地下室的桩基,受到地下室开挖段桩身侧摩阻力的影响,获得的有效桩长单桩极限承载力的准确性大为降低。双护筒技术是在开挖段利用内外护筒将开挖段桩身与桩周土隔离,完全消除开挖段桩侧摩阻力的影响,可以得到准确的有效桩长单桩极限承载力。该文通过一个工程实例,详细介绍了双护筒技术在大直径灌注桩静载试验中的应用,可为类似的基桩静载试验提供参考。

The static load test is usually carried out on the ground.For the pile foundation with basement,the accuracy of the effective pile length and the ulti-mate bearing capacity of a single pile is greatly reduced due to the influence of the side friction of the pile body in the excavation section of the basement.The double pile casing technology uses the inner and outer pile casings to isolate the pile body in the excavation section from the soil around the pile,completely e-liminating the influence of pile side friction in the excavation section,thereby obtaining accurate single pile ultimate bearing capacity of effective pile length section.Through an engineering example,this paper introduced the application of double casing technology in the static load test of large-diameter cast-in-situ piles in detail,which has reference significance for the static load test of similar foundation piles.