Rail transit is like the meridians of a city, and the trenchless machines that connect all kinds of nerve endings are like "underground swimming dragons," driving forward to build up the city. Recently, at the construction site of the Yaoyuan Road Station on Hefei Rail Transit Line 8, the XCMG XDT46*69 rectangular pipe jacking machine successfully broke ground, advancing at full speed to open up the city's north-south meridians.

Yaoyuan Road Station is the third station of Phase I of Line 8. Entrances 1, 2, and 5 cross over the Fuyang North Road Viaduct, and Entrance 1 is the section for this rectangular pipe jacking construction. This section has an overburden thickness of about 5.7 m and a length of about 43.67 m. Along the way, it passes through 36-hole 10 kV power conduits and a φ1200 water supply pipe, with a minimum clear distance of only 1.8 m, placing extremely high demands on ground settlement control.

With high settlement control requirements, the XCMG XDT46*69 faced major tests from both geological conditions and construction speed. The XCMG XDT49×69 pipe jacking machine has a compact structure and short body length, meeting the construction needs of this small working shaft. It adopts an overall upper-and-lower assembly structure, bringing great convenience to equipment transportation and on-site assembly.

In response to the project's difficult problem of high settlement control requirements, the XDT46*69 rectangular pipe jacking machine was optimally designed in terms of grouting and soil conditioning channels. It uses high-precision earth pressure sensors to monitor pressure changes at multiple parts of the soil chamber in real time, precisely controlling the balance between jacking speed and soil discharge, ensuring smooth jacking while reducing soil settlement and maintaining ground stability.

The broken bricks and stones along the jacking section were another "roadblock" during the project's jacking process. To address this, XCMG optimized the design of the hydraulic-drive screw conveyor. Compared with motor drive, its torque is more than doubled. At the same time, a manhole passage is reserved in the casing, making it convenient for personnel to remove obstacles that are difficult for the equipment to clear, fully ensuring construction safety.

Difficult and major projects require sufficiently robust equipment and, even more, high-quality service support. Speaking of the services provided by XCMG Foundation for the project, the project party praised: "Since the equipment entered the site, XCMG Foundation has provided dual support in technology and service for project construction. From assembly and commissioning to emergency maintenance, on-site service personnel have provided full-process tracking and support, offering efficient support for the project's efficient progress!"

In the Paihe River sewage interception and diversion project of the Hefei Yangtze-to-Huaihe River Water Diversion Project, an XCMG pipe jacking machine achieved a successful 2.4 m diameter, 1187.5 m ultra-long-distance breakthrough, a first in China; the XCMG XDT50*70 rectangular pipe jacking machine achieved a construction efficiency and soil discharge rate of 40 cubic meters per hour in the Zhengzhou railway project; in the Central Yunnan Water Diversion Project, XCMG pipe jacking machines set a construction record of up to 15 m of daily excavation in long-distance hard rock projects... Through repeated entry into and breakthrough from the soil, the reliability and advanced nature of XCMG pipe jacking machines continue to be proven!

As the cumulative breakthrough distance continues to increase, XCMG pipe jacking machines continue to accelerate the pace of urban rail transit construction, making urban meridians unobstructed and bursting with vitality!