From May 18 to 20, 2018, "The 2nd railway reinforced soil technology seminar" jointly organized by the reinforcement professional committee of CIGES and other units was held in Xichang City, Sichuan Province. CCTV reporters conducted a follow-up interview throughout the process. On May 21, CCTV's "Morning News" reported it with title "The first use of new-type of reinforced earth retaining wall for Chengdu-Kunming Railway", which was the first time that reinforced earth technology was broadcast on CCTV
In recent years, railroad industry of China has flourished, with the main field of railroad construction in passenger railroad lines like high-speed railways, inter-city railways and municipal railways. Foundation, bridge and tunnel are the main underline engineering affecting investment for railroads. Currently, the proportion of tunnels and bridges is relatively high in passenger railroad lines. In order to lower the construction cost further, one of the effective means adopted is by enhancing foundation. Where railway lines pass through cities, stations and scenic spots, subgrade retaining structure is suitable. Reinforced earth retaining wall as light retaining structure is the key development field of subgrade engineering in China in the future. The structure has the following characteristics: first, it saves land. Compared with the conventional slope subgrade, the 6-meter-high reinforced soil retaining wall can save an area of 27 mu per kilometer and about 60000 m3 of earthwork filling; Second, the project cost is low, which saves about 40 ~ 50% of the investment compared with the conventional gravity retaining wall; Third, it has good seismic performance, especially suitable for construction in seismic areas such as Chengdu-Kunming railway; Fourth, the overall stiffness is high, which can meet the strict requirements of high-speed railway for settlement deformation.
In order to give full play to the technical and economic advantages of reinforced earth retaining wall, in recent years, China Railway Corporation has organized experts and scholars to tackle key technical problems, developed geogrid suitable for passenger dedicated railway, manufactured according to railway special standards and new-type reinforced earth retaining wall with composite integral rigid panel with independent intellectual property rights, and carried out pilot construction in Chengdu-Kunming railway. This technology is going to promote technological innovation of subgrade engineering, coordinate with “One Belt and One Road” plan, improves the competitiveness and technology of Chinese railroad worldwide, all of which is meaningful.
In long term, because of the omission of material technology standard revealing railroad traits and demands, and the mass number of Chinese manufacturers for geosynthetics, the product quality varies, no standards for design, construction, inspection and acceptance, quota and certificate are depended on, which all make the project application level low. To fulfill the requirements of geosynthetics for railroad foundation, standardize the geosynthetics’ quality for railroad projects, improve application level, promote standardized, normalized geosynthetics, China Railway Corporation has organized relevant domestic experts in compiling geosynthetic technology standard series for railroad projects in nine books, which fill in gaps of railroad industry.
The promulgation and implementation of standards for geosynthetics in railroad projects, along with the relevant railroad construction standards like current railroad foundation design specifications and general reference drawing, have formed a complete technology standard system. This is facilitation for improving the application of railroad geosynthetics and promotion for ensuring the quality of railroad projects.
