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目的:研究带承台静钻根植竹节桩的抗压承载性能,承台在荷载传递过程中所起作用,带承台静钻根植竹节桩的桩侧摩擦性能和桩端承载性能。创新点:通过带承台静钻根植竹节桩的现场静载试验对其抗压承载性能进行分析。方法:在预制桩制作过程中在桩身安置钢筋应力计(图1),通过含有钢筋应力计的试桩的静载试验对其抗压承载性能(图7和8)、各级荷载作用下的桩身轴力(图9和10)、承台承载性能(图11和12)、桩侧摩擦性能(图18)以及桩端承载性能(图19和20)进行分析与研究。结论:1.静钻根植工法通过搅拌注浆能够改善承台下部土体性质,在静钻根植桩中设置承台能充分发挥静钻根植工法的优势,在该种桩基中设置承台比较合适;2.承台的存在使桩周土体产生沉降,使得试桩上部桩土相对位移较小,从而使试桩上部桩侧摩阻力减小,试桩下部土体所提供的侧摩阻力相比灌注桩都有所提高;在粘性土中试桩桩侧摩阻力值为灌注桩的1.25倍,在砂性土中达到2倍,说明试桩中水泥土-土体接触面摩擦性能优于灌注桩混凝土-桩周土体接触面的摩擦性能,且在砂性土中提高程度更大;试桩桩端荷载位移曲线基本呈线性,与双折线模型相似;由于有水泥土的渗入,桩端土的强度得到提高,使桩端承载性能也得到提高。
OBJECTIVE: To study the compressive loading behavior of piles bearing static bearing roots of bamboo piles, the role of caps in the process of load transfer, the pile-side friction performance and the pile-end bearing performance of bamboo-piled bamboo piles with cap. Innovative point: through the bearing static bearing bamboo root pile static load test on the site of its compressive loading performance analysis. Methods: The reinforcement stress meter (Fig. 1) was placed on the pile during the manufacture of precast piles. Compressive loading capacity (Fig. 7 and 8), static load test of test piles containing reinforcing steel stress meter, (Figs. 9 and 10), the bearing capacity of the bearing platform (Figs. 11 and 12), the friction performance of the pile side (Fig. 18) and the bearing capacity of the pile tip (Figs. 19 and 20). The conclusions are drawn as follows: 1. The static drilling and rooting method can improve the soil properties of the lower part of the cap by stirring grouting, and the advantage of the static drilling and rooting method can be fully exerted by setting the cap in the static drilling and rooting pile. 2) The existence of cap causes the settlement of soil around the pile, so that the relative displacement of pile and soil in the upper part of the test pile is small, so that the frictional resistance of pile in the upper part of the test pile is reduced, and the side frictional force Compared with the bored pile has improved; in the clay test pile lateral friction value of 1.25 times for bored piles, sandy soil to reach 2 times, indicating that the test soil cement - soil contact surface friction excellent performance The frictional performance of the soil-cement contact surface of the cast-in-place concrete pile is higher than that of the soil, and the degree of improvement is greater in the sandy soil. The load-displacement curve of the pile tip is basically linear, similar to the double-break line model. Due to the infiltration of cement- The strength of the pile tip soil is improved, so that the bearing capacity of the pile end is also improved.