路桥结合部位水毁破坏规律研究

Study on Flood Damage Rule of Road-bridge Binding Site

为进一步揭示公路桥梁工程中路桥结合部位水毁破坏规律,依据Fr相似准则,采用正交试验设计方法,着重探析模型伸入水流长度、与水流方向夹角、坡比及有无防护措施对模型水毁破坏的影响程度;ADINA有限元数值计算与模型试验对比分析,两者相吻合。研究表明:模型伸入水流长度分别设为20,40 cm和60 cm工况条件下,水流冲刷或浸泡作用对模型结构体造成的破坏程度逐渐加深,亦即模型伸入水流长度越长,水流对模型结构体破坏程度越严重;模型与水流方向夹角分别设为45°,90°和135°工况条件下,当模型与水流方向夹角为135°时,模型结构体受水流冲刷或浸泡作用后在其周围形成的堆积物体积量大且分散,冲刷深度显著,模型几乎完全破坏;设有一定坡比的模型,坡面能使水流流速产生有效分解,具有较强的抗冲刷能力;采取注浆层或围堰防护措施可对模型结构体起到完全的保护作用。

In order to further reveal the flood damage rule of road-bridge binding site in highway bridge engineering,according to the Frsimilarity criterion,by adopting the orthogonal experiment design method,we emphasingzed exploring and analysing the influence degree of model length extends into flood,angle between model and flood flow direction,slope ratio and whether protection on the flood damage of the model. By contrasting and analyzing ADINA finite element numerical and model test results,both fit perfectly. The research result shows that（ 1） under the working conditions of model length extends into flood is 20,40,60 cm respectively,the destruction degree of the model caused by scouring or soaking of water flow gradually increased,namely,the longer the length of model into the flood flow,the more serious the damage extent of the model structure;（ 2） under the working conditions of the inclination angle is designed at 45°,90°,135° respectively,when the angle between the model and the flood flow direction is designed to be 135°,after the water flow scouring or soaking the model,theebulk of the deposits are lager and dispersed,the scour depth is significant,and the model is almost completely destroyed;（ 2） with an assumed certain slope ratio,the slope surface could effectively decompose the flow velocity,and has strong anti-scouring capability;（ 3） the protective measures of grouting layer or cofferdam could protect model structure completely.