A few days ago, is known as "north China first pit" tong yu heavy industry co., LTD. Die workshop foundation pit supporting and underground water control project has entered the construction to an end, the project has been done during the National Day holiday all thick water, such as soil mixing wall construction, equipment used for jintai combines hydraulic slotting machine equipment technology and deep mixing technology SC55 double mixing rig.

The energy-saving and material saving technology and equipment upgrading project of high-end equipment core components of Tongyu Heavy Industry is a provincial key project in 2022, and it is one of the few ultra-deep foundation pits in North China. The total investment is planned to be 760 million yuan. The project includes the construction of Tongyu Heavy Industry forging die workshop, die forging press, pump house foundation pit and pile foundation. The construction period is 160 days. The foundation pit in the section of die forging press and pump house is roughly an irregular rectangle, with an east-west length of about 91.5 and a north-south width of about 34m. The circumference of the foundation pit is about 261.70m. The excavation depth of the foundation pit in the section of pump house is 11.5-13.5m, and the excavation depth of the foundation pit in the section of press is 11.5-26.0m.

According to the engineering geological conditions, hydrogeological conditions, excavation depth of foundation pit and surrounding environment of the construction site, the construction project department finally decided to select Jintai SMC drilling rig.

The characteristics of the drill:

1, the wall size, depth, grouting amount, perpendicularity and other parameters of high control accuracy, uniform mixing, good quality of the wall;

2. The wall thickness is 0.7m~1.2m;

3, all kinds of foundation pit shape can be constructed, convenient corner;

4, milling wheel torque up to 8~10t.m, suitable for a variety of complex strata, can be into the rock to the weathering layer, the strata adapt to a wide range;

5, milling rotation number of 0~25rpm;

6, pile length can reach more than 60 meters.

The wall thickness of the site is 800mm, and the depth is -40.50m~53.50m. Before the formal construction, Jintai SC55 double wheel stirring drill shall test the wall as required by the construction party. Jintai SC55 double wheel stirring equipment meets the expectations, with high construction efficiency and excellent wall quality. After the wall is finished, the core is taken without breaking. The hardness is much higher than the design requirement of 0.8MPa, and the impermeability is much higher than the design requirement. It has been well received by Tianjin Hecheng Foundation Engineering Co., LTD and the general contractor of the project (Tianjin Hecheng Foundation has completed 15 similar projects from 2017 to 2022, and has rich experience in deep foundation construction). On this basis, the construction machinery, construction technology and construction parameters are determined.

On the 78th day of construction, 118 impermeable walls have been completed. Among them, 50 pieces of cutoff wall with a thickness of 800mm and a depth of 40.5m can be completed in an average of 5 hours. A total of 68 pieces with a thickness of 800mm and a depth of 53.5m were completed in an average of 8 hours. Now the equipment is transferred to Tianjin to prepare for the next project.

SC series dual-wheel stirring drill is an innovative product and mature product independently developed and manufactured by Shanghai Jintai for the construction of underground diaphragm wall through "deep milling and stirring process" in view of complex geological conditions. As soon as the product was launched in 2010, it has achieved a great response in the market. It has first experienced the test of typical complex geological conditions such as clay, fine silt, pebble and moderate breeze rock, and then has been hunted by similar competitors in various regions. Finally, Jintai SMC drilling rig is superior to the competitors with giant posture technology, and the construction efficiency and equipment stability indicators have reached the international advanced level. In terms of product cost performance, Jintai SMC drilling rig is significantly better than the similar products of foreign brands. Editor/Xu Shengpeng