喜马拉雅山区公路桥涵病害类型及特征研究

Damage Types and Characteristics of Highway Bridges and Culverts in the Himalayas of China

以喜马拉雅山区公路桥涵作为研究对象,基于现场典型病害调查数据,系统论述了喜马拉雅山区公路桥涵病害类型、发育特征以及影响因素,提出了相应的病害整治措施建议。调查结果显示,喜马拉雅山区公路桥梁上部结构梁板铰接缝与翼缘渗水泛碱病害和桥面铺装病害较为普遍,病害率分别为25%和42%。下部结构的桥墩病害主要表现为基础冲刷(12.5%)、桥台台前护坡和耳墙破损(25%)以及桥台背墙渗水、腐蚀、掏空(29.17%)。桥梁附属构造物常见病害为伸缩缝病害、锥坡病害以及导流工程病害等,其中62.5%的桥梁病害出现在伸缩缝位置。涵洞的主要病害主要有涵洞盖板和翼墙开裂倾斜、涵洞进出口堵塞、波纹管涵断裂以及涵背跳车,并且大约60%的涵洞病害位于多年冻土区涵洞进出口位置。公路桥涵工程病害主要是由于环境因素(气候环境、地形地貌、人类活动)和工程因素(设计、施工、养护、建筑材料)所致。因此,建议建立喜马拉雅山区公路桥涵病害数据库,形成“空-天-地”一体化综合监测系统,研发病害防治新技术,做好定期养护维修,提高公路桥涵的服役性能。

The high altitude,complex and diverse topography,sensitive climate characteristics and large carrying capacity pose great challenges to the long-term performance of highway bridges and culverts in the Himalayas of China.Based on the survey data of typical damage in the Himalayas of China during the second Tibetan Plateau scientific expedition and research,this paper systematically analyzes various types of engineering damage of highway bridges and culverts,and proposes corresponding control measures.The investigations indicated that about 42%of bridge damage is related to deck pavement.Water seepage and alkali-flooding in the hinged joints and flanges of the superstructure of highway bridges are common forms of superstructure damage.Foundation scouring is the main form of the bridge pier damage(12.5%).The primary damage forms of bridge abutments are damage to slope protection and ear walls in front of abutments,water seepage,corrosion,and hollowing of abutment back walls.The damage of bridge ancillary structures can be categorized as expansion joint damage,cone slope damage,and diversion engineering damage,with 62.5%of bridge damage occurring at the expansion joints.The damage types of culverts include subsidence,cracking or dislocation of wing walls,blockage of culvert inlet and outlet,fracture of corrugated steel culverts,and vehicle jumping at the culvert back.Around 60%of culvert damage occurs at the inlet and outlet,and is concentrated in the permafrost region.The damage of highway bridges and culverts engineering is mainly caused by environmental and engineering factors,such as climate environment,landform,human activities,design,construction,maintenance,and building materials.Therefore,it is recommended to establish a database of highway bridges and culvert damage in the Himalayas,develop a comprehensive monitoring system,develop new damage prevention technology,prioritize regular maintenance,and improve the service performance of highway bridges and culverts.