How To Realize The Mechanization of The Whole Process of Construction of Zhejiang Jiaotong Yanxiaxu No.2 Tunnel?

In order to further implement the “machine reduction, machine replacement” management concept, and constantly improve the highway mountain tunnel safety management capacity, and promote the modernization of the industry's governance system and governance capacity, September 3 to 4, Zhejiang Province, highway mountain tunnel mechanization of the whole process of construction promotion will be held in Taizhou.

    The participants visited the drilling of multi-arm rock drilling cart and double curved arm rock drilling cart, installation of steel arch frame installation cart, second lining cart lining and other work sites, and listened to the experience and advantages and disadvantages of using domestic and imported equipments, as well as the role of informatization technology in enhancing the tunnel construction environment and emergency management.

Yanxia Xu No.2 Tunnel

The Yanxia Xu No. 2 Tunnel of the Yongtaiwen Expressway renovation and expansion project, undertaken by Zhejiang Jiaotong Group, has a total length of 3643 meters, of which 74% is surrounded by Grade III surrounding rock. The section adopts the original two-way four lane road on both sides, and the expansion plan is to add three lanes. According to the requirements of the Provincial Department's Ping An Centennial Quality Project and the Leading Office of Tunnel Mechanization Construction Tasks, the Yanxia Xu No. 2 Tunnel has innovatively upgraded its "nine sets" and actively introduced "5+N" complete sets of equipment, including five new hyperbolic arm rock drilling trolleys, new arch installation trolleys, wet spraying manipulators, new gantry free secondary lining trolleys, automatic hanging cloth trolleys, intelligent steam maintenance trolleys, and other ten "sharp tools". Realize mechanization of the entire process from excavation, initial support, waterproofing and drainage to secondary lining, maintenance, etc. Intelligent flow production empowers safe and century old quality tunnels with new quality productivity, greatly improving construction efficiency and economic benefits.

Excavation is the core part of tunnel construction. Based on the principle of practicality, the project continuously analyzes the rock drilling rig. Imported fully automatic three arm rock drilling rig and domestically produced double curved arm rock drilling rig are used to compete on the left and right tunnels of the Xu 2 Tunnel under the rock. Comparative analysis is conducted from multiple dimensions such as quality, safety, efficiency, cost, and application prospects. Based on the application effect, it is summarized that:

Imported three arm rock drilling rig

The number of people working on the palm surface of imported fully automatic three arm trolleys can be reduced from 16 to 3, and the time for setting up a 4-meter gun hole is about 1 minute and 40 seconds. The operator can complete the palm surface drilling in the operating room, with precise positioning of the gun hole, good light blasting effect, and high residual rate of the gun hole. However, the equipment is expensive, the operator is scarce, and the import of core accessories takes a long time. It is mostly suitable for full section working conditions and other shortcomings are prominent.

Domestic hyperbolic arm rock drilling rig

Although the construction accuracy and automation level of Uniroc's face drill rigs are inferior to imported trolleys, and manual positioning operation is required for drilling holes, the number of workers on the palm face can also be reduced to 3, and the time for setting up a 4-meter borehole is about 2 minutes. After upgrading and transformation, the quality is slightly inferior to imported trolleys, and the safety performance is basically similar. However, the purchase price and maintenance cost are less than 1/5 of imported trolleys, and it is suitable for various working conditions such as full section and step method, and has more promotion prospects.

The vertical arch loading trolley is an important part of ensuring the stability and safety of the surrounding rock. The installation of the arch frame can be completed in the factory by assembling the prefabricated platform and welding the connecting reinforcement mesh. The first introduction of arch frame installation trolley in tunnel installation, bidding farewell to traditional shoulder lifting and hand lifting, can adapt to various working conditions such as full section and step method, achieving a new transformation. The project collaborates with the manufacturer to improve and optimize the grip strength and flexibility of the robotic arm, achieve intelligent grasping and positioning docking, significantly reduce labor intensity and operation time, achieve precise construction, and effectively enhance intrinsic safety.

The new type of gantry free digital lining pouring trolley adopts tunnel anti void monitoring technology to prevent common quality problems of arch void. It uses digitalization to achieve online monitoring of pumping volume, mold temperature, arch pressure, etc., sound and light alarms, and traceability of key parameters to improve tunnel quality.

Technological innovation is the driving force of new quality productivity. Zhejiang Jiaotong University has formed a strong alliance with Wuxin Equipment, focusing on equipment priority upgrading and installing a self balancing and angle control system for the double curved arm rock drilling trolley arm to solve the problem of drilling accuracy. The mechanical arm grip and flexibility of the arch installation trolley have been improved, greatly enhancing the efficiency of arch installation for holes and achieving safe, efficient, precise, and neat handling of arch segment units.

Taking the mechanization pilot of the entire process of the tunnel as a breakthrough, forging independent innovation, practical application, and striving for excellence, Zhejiang Jiaotong Yongtaiwen has expanded the Yanxia Xu No.2 Tunnel, creating a "new demonstration" of safe and century old quality tunnels.