长沙磁浮快线低置结构关键技术标准优化研究

长沙磁浮快线低置结构技术标准主要包括轨道梁结构和路基工程两方面内容,其中轨道梁的梁型、防错台构造、垫层以及路基工程的路基面宽度、基床厚度、线间排水等关键技术标准存在一些问题,主要表现为存在技术缺陷、设计偏于保守、工程投资偏高等。针对这些问题进行理论分析和研究,并提出优化措施。研究成果及结论为:(1)低置结构轨道梁宜采用U形梁,轨道梁节间伸缩缝处宜采用传力杆防错台措施,轨道梁基底宜设置碎石垫层,施工时可掺5%水泥填筑;(2)路肩宽度一般取为1.5 m,当两侧路肩有信号灯等站后设备时,可局部加宽路基面;(3)路基基床厚度可采用1.8 m,其中基床表层厚度为0.3 m,基床底层厚度为1.5 m;(4)线间汇水宜利用轨道梁上部梁体的节间缝进行排水,同时线间回填层顶面应做好防排水措施。

Optimization of Key Technical Standards for Ground Structure of Changsha Maglev Express

The technical standards about ground structure of Changsha Maglev Express include the track beam and the subgrade. There are some problems in the key technical standards such as beam type, anti-stagger platform structure, cushion layer in track beam engineering and formation width, thickness of foundation bed and inter-line drainage in subgrade engineering. The main problems are technical defects, insufficient design and high investment. This paper conducts theoretical analysis and research on these problems and puts forward optimization measures. The research results and conclusions are as follows:(1) U-shaped beams should be used for track beam in ground structure areas, force transmission poles should be used to prevent staggered platform of joints between track beams, gravel cushion should be installed on the base of track beams, and 5% cement should be added to fill the cushion during construction.(2) The shoulder width is generally 1.5 m. When the shoulders of both sides of the subgrade have signal lights and other post-station equipment, the surface of the subgrade can be widened.(3) The thickness of the roadbed should be 1.8 m, the surface thickness is 0.3 m, and the bottom thickness is 1.5 m.(4) Inter-line catchment should be drained through the joint of the upper beam of the track beam. At the same time, waterproof and drainage measures should be taken on the top of the backfill layer.