China News Service, Wuhan, September 26 (Wang Guoyi, Qumanman, Xu Jinbo) The China Railway Eleventh Bureau Group announced on the 25th that the bureau participated in the construction of the Ping (xiang) Lian (hua) Expressway in Jiangxi Province and opened to traffic on the same day. So far, the journey from Lianhua County to Pingxiang City has been shortened from one and a half hours to 40 minutes.
The total length of Pinglian Expressway is about 75.2 kilometers. It adopts two-way four-lane standard construction. It starts from Pingxiang to Hongkoujie (Ganxiangjie) Expressway in the north, to Lianhua County Quannan Expressway (Jian to Lianhua section) in the south, and connects to Lianhua through Pingxiang. 4 counties (districts) and 9 townships (towns), including Economic and Technological Development Zone, Anyuan District, Xiangdong District, and Lianhua County, are a fast track in the western part of Jiangxi Province, and are also the most expensive per kilometer of expressway projects in this province. The highway with the most complicated geological conditions and the most difficult construction.
The picture shows the beautiful scenery of Pinglian Expressway, photo by Liang Xuewang
According to reports, there are many geological disasters such as karsts, landslides, and mudslides in the sections of the Pinglian Expressway, and the distribution is very dense, and the topographical drop along the line is large, there are many sections of high filling and deep excavation, and the amount of high slope protection works is large. The bridge-to-tunnel ratio of the whole line is as high as 43.2%, which brings great difficulty to the construction.
The highway passes through two national forest parks, and there are many water sources and aquatic protection areas. The construction requires high environmental protection of water and soil.
Among them, the Lianhua Tunnel constructed by the Second Company of China Railway 11th Bureau is a key control project of the entire Pinglian Expressway. It is the tunnel with the most complicated geological conditions in the history of Jiangxi Expressway construction and is called the "Jiangxi Geological Museum".
The tunnel traverses 10 fracture zones, the rock mass is very fragmented, the hydrogeological conditions are complex, the water permeability is extremely high, the fissures in the tunnel site are dense and easy to gush water, and the geological environment is rare in China.
Since the start of construction of the Lianhua Tunnel in October 2018, there have been many occurrences of tunnel face collapse, water gushing, large deformation of the surrounding rock, cracking of the initial support, and limit intrusion during the construction.
In September 2020, a large amount of water gushing occurred at 1,772 meters in the left tunnel of the tunnel, with a water gushing of about 700,000 cubic meters, which brought huge difficulties to the tunnel excavation construction.
The picture shows crossing the lotus tunnel called "Jiangxi Geological Museum" by Chen Jinrui
To this end, the project department optimized the construction plan through scientific and technological research, adopted the man-vehicle separation system, micro-step excavation method, "five-line method" and other technological construction methods, and introduced wheeled water trench cable trough trolleys and large-scale construction methods in time. Complete sets of mechanized equipment such as clearance stainless steel lining trolley, protective plate automatic paving trolley, dobby rock drilling trolley, etc., using machinery instead of labor.
Measures such as pre-grouting to block water, strengthening the support of the tunnel structure, and the use of root canal technology to support the weak surrounding rock section of the tunnel in advance have ensured the steady progress of the tunnel construction.
Pinglian Expressway is an important part of the "one vertical" expressway network of "three horizontals and one vertical" in Pingxiang City, Jiangxi Province.
After opening to traffic, it will further improve and strengthen the transportation connection and traffic radiation of the regional road network, greatly strengthen the connection between the western Jiangxi region and the Changzhutan urban agglomeration, and promote all-round and multi-domain exchanges in the economic and trade, investment, humanities, tourism, etc. between the western Jiangxi and the surrounding areas. cooperate.
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