一种可消除桩基负摩阻力的伞杆桩

An Umbrella Rod Pile Which Can Eliminate Negative Friction Resistance of Pile Foundation

桩基负摩阻力的问题由来已久,国内外关于消除桩基负摩阻力的方法多种多样。本文结合实际工程案例,按照桩基负摩阻力产生的机理进行理论计算,提出一种可消除桩基负摩阻力的类伞杆桩。其工作原理是桩外套管随着土的沉降而向下滑动,直至土沉降稳定后桩外套管正好滑动至弹簧三角钢片固定装置附近,桩外套管通过弹簧三角钢片固定装置与桩基实体建立连接使两者共同工作。通过理论计算和实际工程对比,得出桩的中性点具有时效性,中性点随着时间的推移而逐步向下,最后趋于一个稳定的范围内。因此,在预估中性点附近设置两组固定装置,当中性点在两组固定装置范围内上下移动时,均能消除负摩阻力且不影响正摩阻力的发挥。

The problem of negative frictional resistance on pile foundations has a long history,and there are various methods at home and abroad to eliminate negative frictional resistance on pile foundations.This article combines practical engineering cases and conducts theoretical calculations based on the mechanism of negative frictional resistance of pile foundations,proposing a type of umbrella rod pile that can eliminate negative frictional resistance of pile foundations.The working principle is that the pile outer casing slides downwards with the settlement of the soil,until the soil settlement stabilizes,and the pile outer casing just slides near the spring triangular steel plate fixing device.The outer casing of the pile is connected to the pile foundation entity through the spring triangular steel plate fixing device to work together.Through theoretical calculation and practical engineering comparison,it is found that the neutral point of the pile has timeliness,and the neutral point gradually decreases over time,eventually reaching a stable range.Therefore,setting two sets of fixed devices near the estimated neutral point can eliminate negative frictional resistance and do not affect the performance of positive frictional resistance when the neutral point moves up and down within the range of both fixed devices.