Hengqin Mango Island tunnel project is a major urban road. The main body of the project is a single-storey shield tunnel. It starts from the south side of Liangang Road, passes through the Monkey Chau channel in the form of shield, and lands at the south side of Sheng Chau 10 Road. The total tunnel length approx2km, where the shield length is about980mAnd the length of the water section is approx500mThe deepest water depth7.3m). In order to meet the bearing capacity and deformation of the tunnel design requirements, the water section of the soft foundation of the tunnel adopts water deep cement soil mixing pile (waterDCM) for preliminary reinforcement.
figure1 Location map of Hengqin Mango Island Tunnel Project (red arrow points)
This project on waterDCMThe total reinforcement area is approx5300㎡, the reinforcement thickness is approx29~36m, the reinforcement quantity is about16Ten thousand square. According to the design requirements, in order to improve the working efficiency and pile quality, deep cement soil mixing pile adopts a four-axis, single-axis pile diameter is1.3m, spacing1.0m, lap width0.3m, the image distance3.5m,4.0m, the replacement rate is approx33%, as shown in the following figure.
figure2 The waterDCMSchematic diagram of pile section
The main soil layer of this project can be divided into five layers, which are respectively from top to bottom13~33mA thick layer of silt,0~9mThick layers of clay,3.5~11.5mFor thick gravel clay, fully weathered sandstone and strongly weathered sandstone, the reinforcement depth should penetrate the silt layer and enter the clay layer at least1m. According to the water depth and reinforcement depth calculation, the reinforcement project requirementsDCMThe hardening depth of the device is not less than or equal to42m.
Our waterDCMThe technology has been successfully applied in the foundation treatment project of the third runway of Hong Kong Airport, and has accumulated rich construction experience. For this tunnel soft foundation reinforcement project, our equipment can fully meet the construction requirements. However, considering the high navigation limit (Honghe Bridge), the equipment needs to remove part of the pile frame before the approach to reduceDCMShip height, and secondary assembly on site to restore the original condition. To this end, our company organized a professional technical team to conduct field investigation. After solving the problem of secondary assembly on the water, the project was negotiated quickly.
At present, our companyDCMThe ship has successfully entered the site, and the pile test has been successfully completed. Now the construction of the project is in full swing. It is expected this year6Complete all the construction tasks at the beginning of the month, which will also start our company on the inland waterDCMThe first shot of construction opens a new chapter!
figure3 DCMPhoto of the second assembly of the engineering ship
figure4 DCMPhoto of engineering ship assembled
figure5 The waterDCMConstruction photos
Shanghai Qiangqiang Foundation Engineering Co., Ltd. has completed more than 1,000 projects in the fields of housing construction, underground space, subway, railway, highway, bridge, tunnel, airport, sea reclamation, and so on. Hundreds of projects it has participated in have won the "Luban Award of China Construction Engineering" or the "Magnolia Award of Shanghai Construction Engineering".Contact Number:400-100-2850