宁波地区单桩极限承载力GM(1,1)灰色模型预测

利用未达到破坏的试桩资料来确定桩基的极限承载力具有重要的工程意义。为此,本文根据灰色理论建立了单桩荷载-沉降关系的GM(1,1)模型,编制了相应的计算程序,并利用宁波地区桩基承载力实测数据验证了灰色预测GM(1,1)模型的可靠性,证明了该方法具有较好的预测精度。最后,对宁波市区2006～2010年的910根预应力管桩的抗压承载力特征值进行预测,结果表明:单桩抗压设计承载力特征值有15%～30%的安全储备。

Gray Prediction of Ultimate Bearing Capacity of Single Pile in Ningbo

It is of engineering importance to determine the ultimate bearing capacity of an individual pile by using the data of in - situ test below limited load. Based on the grey theory, GM （ 1,1 ）, a grey model of load - settlement relation for single pile is established and relative calculation program is developed. The test data in the test field is used to ascertain the reliability of the model of GM （ 1,1 ） in NIngbo. The result shows that the GM（1,1） is reliable and has good prediction precision. Besides, the ultimate bearing capacity eigenvalue of 910 prestressed concrete pipe piles in Ningbo during the years 2006 -2010 are taken as examples to be predicted, and it is shown that the ultimate bearing capacity design value can be improved properly by 15% -30% to give full play to the bearing capacity of an individual pile.