荒漠区沥青路面拱胀病害特征调查与成因分析

Characteristic Investigation and Cause Analysis of Asphalt Pavement Arching and Swelling Diseases in Desert Areas

摘要: 针对南疆干旱荒漠区沥青路面拱胀病害问题，以G30₁₂阿克苏至喀什高速公路为研究对象，综合采用现场调查、钻芯取样、全断面挖探、温度监测及室内试验等方法，系统分析了病害特征及成因机制。结果表明：拱胀病害主要分布于极端温差显著、盐渍化严重的干旱半荒漠区，具有显著季节性特征，夏季为高发期；病害表现为水泥稳定砾石基层的横向或Z字形隆起，基层以下结构相对完好；拱胀处基层芯样强度显著降低，$S{O}_4^{2-}$ 含量超标，盐分垂直分布呈路基土 > 下基层 > 上基层的浓度梯度特征；拱胀病害是由温差导致的“热胀”和硫酸盐侵蚀引发的“盐胀”共同作用所致。

Abstract: In view of the arid desert area of southern Xinjiang asphalt pavement arching and swelling disease problem, this study takes G30₁₂ Aksu to Kashgar highway as the research object, adopts on-site investigation, drilling core sampling, full-section excavation and temperature monitoring methods, combined with indoor tests to systematically analyze the characteristics of the disease and the causes of the disease. The results indicate that: arching/swelling primarily occurs in arid semi-desert areas featuring extreme temperature differentials and severe salinization, exhibiting marked seasonality with peak incidence during summer. The disorder manifests as transverse or Z-shaped upheavals within the cement-stabilized gravel base course, while subbase and subgrade structures remain relatively intact. Core samples from affected areas show significantly reduced strength, excessive $S{O}_4^{2-}$ content, and a vertical concentration gradient of soluble salts: subgrade > lower base > upper base. The arching/swelling pathology results from the synergistic effects of “thermal expansion” induced by temperature differentials and “salt expansion” caused by sulfate erosion.