为研究水泥土复合桩水平承载性能,开展水泥土复合桩水平承载性能模型试验,对比分析水泥土加固前后单桩极限承载力、桩身弯矩和桩周土抗力变化规律;考虑桩周土径向非均质性来修正初始地基反力模量和极限土抗力,提出一种适用于水泥土复合单桩水平承载性能的简化p-y曲线模型,并与试验结果进行对比,验证该简化p-y曲线模型的合理性。结果表明：相比未加固桩,加固桩极限承载力得到明显提高,2种加固宽度下单桩极限承载力分别提高5.34倍和2.68倍;无论加固桩或未加固桩,桩身弯矩随荷载和深度变化趋势大致相同,最大弯矩点位置不同,加固桩最大弯矩点位于泥面附近;水泥土加固有效提高桩身土抗力,进而提高桩基水平承载性能;对比试验结果发现,该文计算值与实测值均吻合较好,验证了该简化计算方法的合理性。
Abstract
In order to research the lateral bearing behavior of cement composite piles, a model test was carried out. The variation law of ultimate bearing capacity, pile bending moment and surrounding soil resistance of single pile before and after soil-cement reinforcement is compared and analyzed. Considering the radial inhomogeneity of surrounding soil, the initial foundation reaction modulus and ultimate soil resistance were revised to attain the simplified p-y curves model. In addition, the simplified method was verified by comparing with the test results. The results show that compared with the unreinforced piles, the ultimate bearing capacity of reinforced piles is significantly improved. The bearing capacity of two kinds of reinforcement width is increased 5.34 and 2.68 times, respectively. Whether reinforced pile or unreinforced pile, the bending moment is same variation tendency along loading and depth, and the maximum moment point is different. The maximum point of the reinforced pile is located near the mud surface. The cement-soil improvement effectively enhances the soil resistance of pile shaft, and then enhances the lateral bearing capacity of piles. The comparison test results show that the calculated values are in good agreement with the measured ones, which verify the rationality of the simplified calculation method. This paper can provide the new design ideas and theoretical reference for offshore wind turbine foundations.
关键词
海上风电 /
桩基础 /
承载性能 /
模型试验 /
p-y曲线
Key words
offshore wind turbines /
pile foundation /
bearing capacity /
model test /
p-y curve
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基金
国家电网鲁能集团有限公司科技项目（52980018000N）
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