大直径扩底人工挖孔桩承载力研究

依托武汉某工程实例,对大直径扩底人工挖孔桩承载力进行了研究,通过岩石极限单轴抗压强度室内试验和深层载荷板试验确定持力层的承载力特征值,采用规范提供的计算公式,用两套试验参数对单桩承载力进行预估,并通过现场单桩载荷试验对计算结果进行验证。研究表明:深层载荷板试验参数预估单桩承载力特征值,明显大于岩石极限单轴抗压强度室内试验计算值,且前者与单桩静载荷试验结果更为接近,可准确预估单桩承载力,进而为后续大直径扩底挖孔桩设计提供可靠参考。

Experimental Research on Bearing Capacity of Large-Diameter Belled Pile

Based on a practical project in Wuhan, the bearing capacity of large-diameter belled pile has been studied by the limits of rock uniaxial compressive strength and deep plate loading test to determine the carrying capacity value of the bearing layer. We used standardized formulas to evaluate by two sets of test parameters characteristic values of pile capacity, and used static load tests to validate the estimated carrying capacity. The results showed that：the estimated carrying capacity of deep plate loading test, which is significantly greater than the uniaxial compressive strength test, is very similar with static load test. The plate loading test can accurately estimate the single pile loading capability, and that can provide a reliable reference for the design of large-diameter belled pile.