斜拉桥斜拉索体系病害分析与处理方案

Deterioration Analysis of Stay Cable System of Cable-Stayed Bridge and The Dealing Scheme

为了延长斜拉索的使用寿命,确保桥梁的安全运营,对海口世纪大桥斜拉索体系进行了检测和养护维修。海口世纪大桥主桥为(147+340+147)m双塔双索面预应力混凝土边主梁斜拉桥,该桥斜拉索上、下锚头锈蚀,PE护套环向裂纹、表面破损。经分析锚头锈蚀主要是由预埋钢管护套、防护罩和不锈钢套管之间的密封胶防水功能失效所致;PE护套环向裂纹和表面破损主要由材料抗老化性能不足、热挤工艺缺陷及施工过程中防护不足,施工工艺缺陷等所致。针对该桥斜拉索病害,采用控制锚具及拉索套管内进水、对既有钢结构加强防护及水流疏导等处理措施,取得了预期的效果。

In order to extend the service life of stay cables and ensure the safe operation of bridge, the stay cable system of the Haikou Century Bridge has undergone inspection and mainte- nance. The main bridge of the Haikou Century Bridge is a （147-I-3404-147） m prestressed con- crete edge main beam cable-stayed bridge with double pylons and double cable planes. The bridge suffers from the deterioration of the erosion at the upper and lower anchorage heads o{ the stay cables, loop cracks and surface damage on the PE sheaths. By analysis, the erosion of the anchor- age heads is mainly caused by the failure of the waterproof ability of the sealer filled in the spaces between the embedded steel pipe sheaths, protective coverings and stainless steel pipes. The loop cracks and surface damage on the PE sheaths are induced by the lose of the aging resistant capaci- ty of the materials, the defects of the hot extrusion technology, the inefficient protective meas- ures in the construction process, and the defects of the construction technology. In the light of the deterioration of the stay cables, the dealing measures of controlling water penetration into the anchorages and the stay cable sheaths, strengthening the protection for the existing steel structures and water dredging system were taken. The measures were proved achieving the expected results.