New Prestressed Retaining Pile Structure System and Reinforcement Method
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摘要: 常规桩锚支护体系中支护桩主筋不能回收，支护任务完成后成为建筑垃圾，造成极大的资源浪费。为响应国家“双碳”战略，提出一种新型可回收主筋的预应力支护桩。对该新型支护桩的结构构造、材料选择、施工工艺流程、回收主筋技术要点等方面进行介绍，对其受力方式和工作机理进行深入研究，基于传统的计算方法，提出一种新的配筋计算方法。为了确定新方法中张拉控制应力的合理取值范围，应用ABAQUS有限元软件进行了数值模拟分析，得到不同工况下新型支护桩的抗弯承载力，并将其与新的配筋计算方法得出的抗弯承载力结果进行对比，结果表明，新的配筋方法仅适用于张拉控制应力不超过300 MPa的情况。Abstract: A large number of reinforcing bars in the conventional pile anchor support structure system cannot be recycled and become construction waste. Under the background of the carbon peaking and carbon neutrality goals, a new type of prestressed support pile with recyclable main bars was proposed. This new type of support pile was introduced from the aspects of structural structure, material selection, construction process, technical points of recycling main bars, etc. The bearing mode and working mechanism of this new type of pile were deeply studied, and a new reinforcement calculation method was proposed based on the traditional calculation method. The rationality of the formula was analyzed. In order to determine the reasonable value range of the tension control stress, ABAQUS finite element software was used to carry out numerical simulation and analysis, and the bending bearing capacity of this new type of support pile under different working conditions was obtained. Compared with the bending bearing capacity calculated by the new reinforcement method proposed, the research shows that the new reinforcement method is applicable to the situation where the tension control stress does not exceed 300 MPa.
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表 1 新型支护桩配筋计算分项数据
$ {\sigma }_{\mathrm{c}\mathrm{o}\mathrm{n}} $
/MPa受压区
角度/(°)抗弯承载力
/(kN·m)压区混凝土
抵抗弯矩M1/(kN·m)压区钢筋
抵抗弯矩M2/(kN·m)拉区钢筋
抵抗弯矩M3/(kN·m)压区混凝土
压力/kN压区钢筋
压力/kN预应力
/kN拉区钢筋
拉力/kN100 92.50 437.99 229.98 101.13 106.87 703.99 322.89 65.47 957.77 150 93.75 434.68 237.22 102.18 95.28 730.32 327.25 229.13 829.40 200 95.25 432.83 245.99 103.42 83.41 762.61 332.49 392.80 701.94 250 96.75 430.37 254.84 104.65 70.88 795.70 337.72 556.46 577.22 300 98.25 427.34 263.77 105.86 57.71 829.55 342.96 720.13 455.22 
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表 2 对照组划分
工况编号 钢筋牌号 混凝土等级 张拉控制应力$ {\sigma }_{\mathrm{c}\mathrm{o}\mathrm{n}} $/MPa 工况1 PSB785 C30 100 工况2 PSB785 C30 200 工况3 PSB785 C30 300 工况4 PSB785 C30 500 工况5 PSB785 C35 100 工况6 PSB785 C35 200 工况7 PSB785 C35 300 工况8 PSB785 C35 500 工况9 PSB930 C30 100 工况10 PSB930 C30 200 工况11 PSB930 C30 300 工况12 PSB930 C30 500 工况13 PSB930 C35 100 工况14 PSB930 C35 200 工况15 PSB930 C35 300 工况16 PSB930 C35 500
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