泡沫轻质土在西藏桥涵台背回填中的应用研究

Application Research of Foamed Lightweight Soil in Backfilling of Bridge and Culvert Abutments in Xizang

摘要: 针对西藏非永久冻土区桥涵台背回填面临的“压实难、沉降大、桥头跳车”等工程痛点，文章以泡沫轻质土为研究对象，通过试验检测、施工监测与对比分析，系统研究其在西藏的高原环境下的材料特性、施工工艺、质量控制要点及重点参数检测方法，并与传统液态粉煤灰回填材料进行性能与工程适用性对比。泡沫轻质土在西藏非永久冻土区台背回填中，可实现无压实施工、沉降量 ≤ 5 mm，较液态粉煤灰在力学性能、施工效率及长期稳定性上更具优势；质量控制核心在于原材料级配、配合比精准度及养护温湿度管理，这为西藏桥涵台背回填提供了新型技术方案，具有显著工程应用价值。

Abstract: To address the engineering challenges of “difficult compaction, excessive settlement, and bridge-head bump” in bridge and culvert abutment backfilling within the non-permafrost regions of Xizang, this study focuses on foamed lightweight soil as the research subject. Employing experimental testing, construction monitoring, and comparative analysis, the study systematically investigates the material properties, construction processes, key quality control measures, and critical parameter detection methods of foamed lightweight soil under the plateau environment in Xizang. Additionally, it compares the performance and engineering applicability of this material with that of traditional liquid fly ash backfill. Results indicate that in abutment backfilling within Xizang’s non-permafrost regions, foamed lightweight soil enables non-compaction construction with a settlement of no more than 5 mm. Compared with liquid fly ash, it exhibits superior mechanical properties, higher construction efficiency, and better long-term stability. The key to quality control resides in the gradation of raw materials, the precision of mix proportions, and the regulation of curing temperature and humidity. This study thus provides a novel technical solution for bridge and culvert abutment backfilling in Xizang, offering substantial engineering application value.