At 16:30 on the 6th, good news came from the construction site of the Ningbo Sanmen Bay Bridge: Shanghai Jintai's full hydraulic reaming drill achieved complete success in test piling. On-site ultrasonic testing showed that two test piles at depths of 27 meters and 46 meters were both expanded from 1.2 meters to 2.2 meters in a single pass, and the reaming effect fully met the expected design specifications. This is the first engineering test conducted by Shanghai Jintai after continuous improvement of its original YKD reaming drilling tools. With this, the Jintai foundation construction equipment family has added another benchmark product.
    The bored reaming cast-in-place pile construction method involves drilling a pile hole formed by the equal-diameter drilling method to a predetermined depth, then opening the reaming cutter of the drill bit to rotate and cut the formation to enlarge the hole diameter. After the hole is formed, a reinforcement cage is placed and concrete is poured to form a reamed pile, thereby obtaining a construction method with greater bearing capacity.
    Using Jintai reaming drills for reamed cast-in-place pile construction has the following advantages:
    1. When the pile diameter is the same, a reamed pile can greatly increase the bearing capacity of a single pile compared with a straight-shaft pile;
    2. While ensuring the bearing capacity of a single pile, a reamed pile can reduce the pile diameter or shorten the pile length compared with a straight-shaft pile, thereby reducing drilling workload and saving time and material costs;
    3. When the total bearing capacity of the foundation is fixed, the use of reamed piles can reduce the number of piles and save investment. Under mud slurry wall protection, it can reduce spoil discharge and lower pollution;
    4. With the reaming process, the designed pile diameter can be correspondingly reduced, or the number of piles can be correspondingly decreased, and the pile cap area can also be correspondingly reduced;
    5. Larger-diameter reamed piles can meet the "one column, one pile" requirements of high-rise buildings;
    6. Compared with traditional mechanical bottom enlargement, the full hydraulic reaming drill can ream at different positions along the pile body as needed. Compared with the mechanical bottom enlargement process, which can only use the pile bottom for support and reaming, this greatly reduces the trouble of bottom cleaning.
    According to public information, the Sanmen Bay Bridge and connecting project is Ningbo's fourth large cross-sea highway bridge after the Hangzhou Bay Bridge, Zhoushan Cross-Sea Bridge, and Xiangshan Port Bridge. The Sanmen Bay Bridge and connecting project is about 55 kilometers long and designed to expressway standards. The route includes four major types of works: tunnels, subgrades, viaducts, and cross-sea bridges.     The reason Shanghai Jintai chose the Sanmen Bridge project as the test piling site for the reaming drill is mainly based on consideration of the particularity of Ningbo's stratum conditions. In Ningbo's strata, silt and clay are widely distributed and covered deeply, so cast-in-place piles are generally deep, and ultra-deep pile types of more than 60 meters are very common. This brings certain difficulties to construction time and project cost, while the reaming method can greatly reduce construction cost and improve construction efficiency.     Shanghai Jintai Engineering Machinery Co., Ltd. was formerly "Shanghai Geological Prospecting Machinery Factory," established in the 1950s. It has more than 60 years of history in the research, development, and manufacture of pile and deep foundation construction machinery. Shanghai Jintai takes it as its mission to promote the comprehensive upgrading of China's underground foundation construction equipment. Adhering to the development philosophy of "building a solid foundation together, creating century-old projects together" and a professional spirit of continuous innovation, it looks to the forefront of world technology and manufactures complete sets of underground foundation construction equipment suitable for China's conditions. At present, it has formed a product cluster of 16 series and more than 60 models, with mainstream products such as SD/SH multifunctional drilling rigs, SG diaphragm wall grabs, ZKD multi-axis drilling rigs, SX double-wheel trench cutters, SC double-wheel mixing drilling rigs, and SQ full hydraulic circulation drilling rigs.