黄土地区高速铁路修建技术创新

研究目的:在湿陷性黄土地区建设铺设无砟轨道的高速铁路,国内外尚无可供借鉴的研究成果和工程经验。黄土的湿陷变形特性,加大了路基、桥梁、隧道等结构物的沉降,影响铁路的稳定性、安全性等。本文结合郑州至西安铁路客运专线工程实践,对综合勘察和路基、隧道、桥梁的关键设计技术创新进行总结。研究结论:在黄土勘察中引入"松软土"的概念,补充完善《铁路工程地质勘察规范》;国内外首次采用埋入式连续桩板路基结构,解决了基底下部厚层黏性土的长期蠕变引起路基下沉问题;全面、系统地提出了大断面黄土隧道的设计原则和安全、快速、经济的施工方法;在高烈度震区长联连续梁上采用4组双向式钢轨伸缩调节器设计技术,在渭南北站采用350 km/h通过式车站桥梁与无砟轨道无缝道岔群一体化设计技术。这些创新技术成为在湿陷性黄土地区修建高速铁路的土建工程成套技术的关键。

The Technology Innovation about Construction of High-speed Railway in the Loess Regions

Research purposes: There is no research and engineering experience to use for reference at home and abroad about the construction of high-speed railway which is ballastless in the collapsible loess regions.The collapsibility deformation properties of loess increased the settlement of the subgrade,bridges,tunnels and other structures,affecting the stability and security of railway.This paper makes a summary of the key design technology innovation about comprehensive investigation,subgrade,tunnels and bridges. Research conclusions:The introduction of the concept of "Loose Soft Soil" in the loess investigation,has made a supplement and improvement for "Code for Geology Investigation of Railway Engineering".At home and abroad for the first time using the embedded consecutive pile-sheet subgrade structure,to solve the long-term creep resistance of the thick layer of clay soil under the subgrade base which would cause the settlement of subgrade.Comprehensively and systematically put forward the design principles and construction method of the large section of loess tunnel which is safely,rapid and economical.In the high-intensity earthquake zone and on the long continuous-beam bridge,the technology of four sets two-way rail expansion joint were used.In the north Weinan station,integrated design technology of pass-type station bridge and gapless turnout group was applied.These innovative technologies are the key to the technology package of civil works for high-speed railway built in collapsible loess regions.