钢筋混凝土咬合筒形灌注桩在基坑工程中的应用研究

Application of occlusal pipe pile cast-in-situ in retaining and protection of foundation excavation

原圆环形桩靴现改进为圆环形带凸边的喇叭形导入软土桩靴,内钢模管进土量提高;分析了排土管的工作原理,内外钢模管与钢盖板连接,以及钢筋混凝土咬合筒形灌注桩实施的过程;钢筋混凝土咬合筒形灌注桩作为基坑围护工程中承受侧向土压力的支护桩,可充分发挥受弯构件的大刚度;与常规地下连续墙相比,节省钢筋与混凝土40%以上,改善挤土性能,以及具有可靠的防渗性能;对于饱和软土地区,是三层及三层以上地下室基坑及轨道交通超深站台最经济的围护结构。

Compared with old type,the new type of pile shoe has knurled trumpet shape which increases the quantity of soil going to steel pipe.The working principle of earth-removing pipe and the connection between steel pipe and steel cover board are present herein.Additionally,notch of steel pipe and steel cover board are analyzed as well as the construction of occlusal pipe pile cast-in-situ.As a retaining pile,occlusal pipe pile cast-in-situ can resist lateral earth pressure in foundation pit engineering and has the characteristics of big stiffness of flexural members.Still,it improves soil extrusion and reliable seepage control.Compared with underground diaphragm wall,it can save forty percent steel and concrete at least.So,occlusal pipe pile is the most economical foundation pit which has no less than three stories underground as well as the extra-deep platform of rail transit.