​At Present, the Longest Drilling and Blasting Tunnel in the Domestic Oil and Gas Pipeline Industry has been Successfully Broken Through

At Present, the Longest Drilling and Blasting Tunnel in the Domestic Oil and Gas Pipeline Industry has been Successfully Broken Through

Recently, the longest drilling and blasting tunnel under construction in the domestic oil and gas pipeline industry, the control project of Huizhua-Haifeng trunk line project, Lianhuashan tunnel, which was investigated and designed by the Southwest branch of China Petroleum Engineering Construction Co., LTD., a central enterprise in Sichuan, was successfully completed, laying a solid foundation for the whole line ventilation and refreshing the record of the drilling and blasting tunnel dedicated to the domestic oil and gas pipeline industry. It has a demonstration significance for the construction of other long and large tunnels of oil and gas pipelines.

Lianhuashan Tunnel is located in the hinterland of Lianhuashan Forest Park at the intersection of Huidong County, Guangdong Province and Shenzhen-Shantou Special Cooperation Zone. It passes through the provincial ecological nature reserve with beautiful natural scenery, high forest coverage rate and superior ecological environment. It has high requirements for engineering construction planning and environmental protection. It is also faced with difficulties such as mountain connection, large relief of terrain, maximum relative height difference of 1001.18 meters, broken mountain, dense mountain boulders and so on. Under many difficulties, the Southwest branch cooperated with the participating units for 4 years to pass through the Lianhuashan tunnel with high quality.

According to Li Shuwei, a level engineer of China Petroleum Engineering Construction Co., LTD., the company went into the site more than 10 times for site selection, while coordinating and docking with the National Energy Administration, Guangdong Provincial Energy Bureau, Shenshan Special Cooperation Zone, Huizhou City government and construction units for more than 10 times for pipeline site selection and construction plans. And fully consider the length of the line and other factors, developed 5 sets of design schemes, after several rounds of expert demonstration, the final line design scheme.

Xu Guojie, head of the survey and measurement professional of the project, said that in view of the large relief and dense vegetation of Lianhua Mountain, the elevation drop from the tunnel entrance to the top of the mountain is 500 meters, and the traffic is difficult, the survey team of the Southwest Branch has carefully planned and organized the survey and measurement personnel to go deep into Lianhua Mountain 15 times for reconnaissance and mapping, and formulated a special survey plan. The topographic map meeting the accuracy requirements was obtained by using the high-precision UAS LiDAR segment flight overall solution scheme. The ground section data was measured and collected by the latest Beidou RTK positioning equipment to obtain high-precision tunnel section data, which provided accurate supporting data for the rapid implementation of the tunnel.

The project manager Hu Wenjun revealed that before the tunnel construction, the Southwest Branch worked together to prepare 10 special construction treatment measures such as fault fracture zone treatment, water-rich area treatment, cave-in and roof fall section treatment, rock burst treatment, slow dip rock section treatment, and carried out risk assessment of collapse, environmental protection, structural design, and pipeline tunnel operation safety. To provide reliable technical support for tunnel construction, provide all-round technical support, comprehensive control of engineering safety and quality from all angles, and ultimately ensure the smooth penetration of the tunnel.