离心模型试验模拟平板载荷试验研究

Study on plate loading test by centrifugal model tests

利用承载力离心模型试验研究平板载荷试验中的承压板尺寸对承载力取值的影响。试验结果表明:基础直径为80 cm和56 cm时的极限承载力相差达27%～40%;在疏松地基(相对密度为34%)情况下,可忽略基础尺寸效应对试验结果的影响。但是在密实地基(相对密度为78%)情况下,《建筑地基基础设计规范》(GB50007—2002)规定的承压板尺寸范围内(56～80 cm)仍然存在基础尺寸效应,即使是80 cm的承压板,其承载力系数达到可忽略尺寸效应时对应的承载力系数的1.2倍。基于离心模型试验结果,提出基础尺寸效应修正式和承压板尺寸换算式,对平板载荷试验结果进行修正。

Through centrifugal model tests, the influence of plate size on the results of plate loading tests was studied. It was shown that the difference of the ultimate beating capacity between f 56 cm and 80 cm plate was up to 27% to 40%. For the loose ground （relative density 34%）, the scale effects could be neglected, but for the dense ground （relative density 78%）, the scale effects would influence the results of plate loading tests in the rang of plate size suggested by Specification for Foundation Design of Construction Ground （GB50007-2002） （56 cm to 80 cm）. Even for the plate with diameter 80 cm, the bearing capacity factor obtained from the tests was 1.2 times of that excluded the scale effects. According to the centrifugal test results, the corrected formulas of scale effect and plate size were introduced and the results of plate loading tests were modified.