鹅公岩长江大桥东锚碇围岩极限承载力GM(1,1)模型预测研究

 重庆鹅公岩长江大桥设计采用悬索桥方案，东锚碇设计为隧道锚，布置在粉质砂岩和砂质泥岩互层岩体中，锚碇及围岩体的变形状态直接影响大桥的稳定和安全。通过 12.5∶1实地结构模型进行锚碇张拉试验，获得了4.6倍设 计荷载下锚碇及围岩体的变形数据。根据对变形数据及荷载*.变形曲线的分析，认为锚碇及 围岩变形较小，变形处于弹性阶段。通过获得的变形数据建立起围岩极限承载力灰色GM（1 ，1）预测模型，预测出岩体极限承载力为设计荷载的6.09～6.15倍，锚碇处于安 全状态，并有足够安全储备。

Limit Bearing Capacity Forecast of Anchorage Surrounding Rock of Egongyan Changjiang Bridge with GM(1,1) Model

The suspension bridge scheme was adopted in the Chong qing Egongyan Bridge. East anchorage used as one of anchors was a tunnel anchor buried in siltstone and sand-mudstone layers of rock mass, and the deformation states of the anchorage and surrounding rock would influence the stability and security of the bridge directly. The deformation data of the anchorage and surrounding rock under the action of 4.6 times design load were obtained by a scale 1∶12.5 structure model test in situ. Through analysing the tested load*.deformation curve it is demonstrated that t he deformation of the anchoruge and surrounding rock is small, being within their elastic stage. Based on the test data, a grey-forcasting model GM(1,1) was established, by which the rock utmost limit bearing capacity is forecasted to be 6.09～6.15 times as much as its design load, the tunnel anchorage is in safe state, and has enough safety storage.