输电线路挤扩支盘桩试验及承载力计算研究

Bearing Capacity Calculation and Test of Squeezing Branch Pile in Transmission Line

本文通过沧州滨海软土地基上进行的挤扩支盘桩与等直径灌注桩静载荷试验，探讨了挤扩支盘桩在输电线路中应用的可行性。根据试验结果，挤扩支盘桩具有较大的抗压和抗拔承载潜能，其抗压和抗拔极限承载力比等直径灌注桩提高11%～20%。按不同技术规范所建议的单桩承载力估算公式进行了承载力计算并与试验值进行分析比较。对规范估算公式和试验结果中桩侧阻力、支盘端承力、桩端阻力在单桩承载力中所占比例进行了对比分析。根据规范计算结果与实测结果的差异，提出了其承载力计算公式的修正建议。

The static loading test for a group of squeezed branch piles and bored piles with equal diameter performed in Cangzhou soft ground were carried out in this paper, and the feasibility of the application of the squeezed branch pile in the transmission line was discussed. According to the test results, the squeezed branch pile has larger potential compression and uplift bearing capacity, which improved at least 20%than that of the equal diameter bored piles. The bearing capacity of single pile was calculated based on the different pile capacity estimation formulas recommended by current technical specifications. The calculated values of the pile shaft resistance, end bearing capacity of squeezed branch pile, and the pile tip resistance ratio in single pile capacity were compared with the corresponding experimental values. Accordance with results of comparative analysis, the proposed amendments of corresponding bearing capacity formulas were figured out.