CRCHI TBMs used in Under River Tunnel Project of Yuan River in Changde in Hunan Province, China, for customer CRCC 14th Bureau Group

First super large-diameter SPB with cutter replacement under normal pressure in ChinaFirst super large-diameter SPB with cutter replacement under normal pressure in China

The under-river tunnel project of Yuan River in Changde is a twin-tube tunnel in the Chinese inland city of Changde. The tunnel connects two sides of the Yuan River, and with its two-way and four-lane, it will promote harmonious development of regions along the river. The tunnel excavation was completed in July 2019. 3360 meters of the twin-tube tunnel (each of 1680 meters long) with an outer diameter of 11.3 meters and an excavation diameter of 11.71 meters were driven by a CRCHI independently developed slurry pressure balance shield machine (SPB), which is the first set super large-diameter SPB with cutter replacement under normal pressure.

As for the tunnel’s vertical section, the maximum longitudinal gradient is 3.54%, the minimum turning radius is 680 meters, the maximum overburden is 18. 2 meters, the minimum overburden is 11.3 meters, the maximum water-earth pressure in the river is 4.5 bar, and the utmost water-earth pressure is 5.5 bar.

Main geology is round gravel soil. Pebble strata is distributed in an area of 400 meters long at the northern part. A small amount of silt interlayer is distributed in the river’s bottom. Soil dig-ability grades are Grade I~III, surrounding rock classification is Grade V. The gravel-cobble stratum, among others, is highly permeable, its permeability coefficient being 120m/d. The maximum particle size of the pebble is 45cm, the range of point loading strength is 0.51~5.21MPa and the uniaxial compressive strength is 73.57 Mpa.

Project challenges
Project challenges are large excavation diameter, complicated hydrogeological conditions and confined water. Due to characteristics of high strength, high permeability and high-water pressure, ensuring stable and safe excavation is a key point for this project.

When the SPB is driven in the gravel-cobble stratum with maximum permeability coefficient of 120m/d for a long distance, underground water will constantly enter the excavation chamber to cause slurry fail to reach the standard. Therefore, muck is difficult to discharge and will be accumulated at the bottom of the excavation chamber. This will increase the wear to the cutting tools and slurry pipes and the frequency of cutter replacement. So, driving in the pebble stratum in a smooth way is a big challenge.

Driving in the clay may cause formation of mud cakes, which will reduce tunneling efficiency. So, preventing formation of mud cakes during excavation is another big challenge.

TBM breakthrough

TBM type and parameters
TBM type: ZTS11710 SPB with cutter replacement under normal pressure
Excavation diameter: 11750mm
Length of shield+back-up gantries: 132 meters
Weight of shield+back-up gantries: 3000 tons
Installed power: 6100 kW
Maximum advance rate: 60mm/min

Innovation points
The mega 12m-level SPB with cutter replacement under normal pressure is applicable in high water pressure and long-distance tunneling and available for high requirement on ground settlement.

The self-developed technology of cutter replacement under normal pressure effectively reduces the risk of workers during cutter change by workers, making the replacement safer and quicker.

Application of a high precision gas-liquid pressure balance control technology guarantees that the pressure is always kept balanced between the tunnel face and the excavation chamber. A big-power slurry circulation flushing system ensures high-efficiency excavation and delivery so as to operate easily and adjust parameters.

CRCHI TBMs used in Under River Tunnel Project

Alloy-toothed crushers at the slurry outlet are hydraulic-driven and have high crushing efficiency.

The SPB uses CRCHI integrated control systems and has stable and reliable performance. The successful development and application of cutter change under normal pressure technology is a big leap for Chinese TBM development technology, filling in the domestic gap in this field. Besides, application of box culvert synchronous installation technology allows for the assembly of precast box culverts parallel to tunneling, effectively shortening the construction period.

Construction performance
  • Maximum daily advance rate is 22m/day
  • Maximum monthly advance rate is 362m/month.

NBM&CW March 2020

Click Here
To Know More / Contact The Manufacturer
Please provide your details we will contact you as soon as possible
Please let us know your name.
Invalid Input
Please let us know your Designation.
Invalid Input
Please let us know your City.
Please let us know your State.
Please let us know your Country.
Please let us know your Contact Number.
Please let us know your email address.
Please brief your query.

CREG Φ15.8m Slurry TBM Solution for Chunfeng Tunnel in Shenzhen

Chunfeng Tunnel is the first bi-directional four-lane highway tunnel in Shenzhen, China, with two decks within one tunnel. The tunnel is 3,603m long; its average radius of curve is R750m and its biggest gradient reaches 49% Read More ...

GHH’s MK-A35 – Ideal for Tunneling & Mass Mining

With the 2020 upgrade of its long-proven MK-A35 model, GHH, German manufacturer of heavy machinery for mining, tunneling, and special civil engineering, presents the first 35-ton class dump truck, already operating in the field Read More ...

Srons Engineers, India’s first company to manufacture SDA Bars, has a strong quality control policy in place

Established in 2015 to support the growing demand of its Rock Hardware products, Srons Engineers is an Indian manufacturer of Rock Bolts, Self-drilling Anchor systems and Self Drilling Anchor Bolt parts like hollow bar & rod Read More ...

Tunneling, Rock Support & Geotechnical Solutions by MIPL & ROBIT

Machino International (MIPL) - a specialist company based in New Delhi, is a leading supplier of Construction, Tunnelling and Geotechnical products. The company has more than 30 years of experience in H.E.P, Road Tunnels, Cavern projects Read More ...

Turkey’s Tough Geology Inspires Robust Machine Design

Driven through a mountain side with 600-m of cover in Central Turkey, the Kargi Kizilirmak Hydroelectric Project is one of the most challenging tunneling projects ever completed in the region. The project is located on the Kızılırmak River Read More ...

CREG’s EPB TBM Ready to Perform in Italy

The Turin-Venice high-speed rail is part of the Pan-European Multimodal Corridor, which traverses the northern part of Italy and connects the northwest to the northeast of the country. It is an important gateway for Western European countries Read More ...

Characteristics & Categorization of Tunnel Fires & Their Mitigation

A fire that develops in a tunnel interacts with the ventilation airflow and generates complicated air flow patterns and turbulence in the vicinity. The heat generated warms up the surrounding air, and in case of a slope inside Read More ...

Mapei: Injection Solutions for Underground Construction

Injection can be defined as the introduction of a material with pressure into the ground or a structure for waterproofing and for consolidating voids, cracks and porosity. Generally, the injection can be categorised as Pre Read More ...

Tunnel Renovation Redefined

During renovation of the Hasselborner Tunnel in Central Hesse, Germany, contractor Baresel used a method they hadn't tried before. Parts of the tunnel lining had to be removed and the areas were subsequently Read More ...

GHH adds Shotcreting Machine to its - Tunneling Equipment Solutions

GHH is offering state-of-the-art and proven IS26 Concrete Spraying (Shotcrete) machine in India. The machine is suitable for shotcreting application in medium and large sized tunnels with cross sections ranging Read More ...

Kishanganga Hydro Power project – A New Power House

Inaugurated by the Prime Minister of India, the Kishanganga Hydro Electric Power project is the first mega hydro power plant to be awarded as EPC to HCC by NHPC. Located at Bandipore in north Kashmir, the Read More ...

Tunneling to Prosperity: Solutions, Equipment and Technologies

India is one of the fastest growing markets for tunnel construction due to various infrastructure development projects underway across the country. Tunnels are required for hydroelectric power projects, for improving road Read More ...

CREG: Tunneling Specialist

China-based China Railway Engineering Equipment Group Co., Ltd (CREG) is a subsidiary of the public- listed China Railway Engineering Corporation (CREC), a Fortune 500 company and a key state-owned company under Read More ...

Intermodality & Last Mile Connectivity - Creating Smart Walkable Spaces

Urban congestion needs to be addressed by encouraging high quality and innovative energy-efficient public transport integrating it with other forms of paratransit, ensuring last mile connectivity; working on Read More ...

Ashram Metro Station - An Engineering Masterpiece

One of the main challenges of constructing a station in the Delhi Metro Network, especially in a busy and densely populated area, is designing it according to the ambience and the limited space allocated. Constructing Read More ...

Transit Oriented Development - Challenges and Proposed Regulatory Framework

Transit Oriented Development (TOD) complements the concept of new urbanism. Compact, mixed-use communities are the answer to suburban problems. Due to the dynamic nature and multiplicity of underlying Read More ...
NBM&CW

New Building Material & Construction World

New Building Material & Construction World
MGS Architecture

Modern Green Structures & Architecture

Modern Green Structures & Architecture
L&ST

Lifting & Specialized Transport

Lifting & Specialized Transport
II&TW

Indian Infrastructure & Tenders Week

Indian Infrastructure & Tenders Week