All About Tunnel Pipe Umbrella Technology Are Here


I. Introduction


A. Definition and Significance of Tunnel Pipe Umbrella Technology


In the realm of tunnel construction, safety and stability are paramount. One innovative method that has garnered attention for its effectiveness in achieving these goals is the Tunnel Pipe Umbrella Technology. This advanced support system involves the strategic placement of pipes or tubes in the tunnel face prior to excavation, reinforcing the surrounding rock and enhancing the structural integrity of the tunnel.

pipe umbrella system

B. Brief Overview of its Applications and Benefits


Tunnel Pipe Umbrella Technology offers a versatile solution for challenging geological conditions such as loose rock mass, water ingress, and high ground stress. By providing proactive support before excavation begins, this technology mitigates risks and facilitates smoother construction processes. Its applications range from highway tunnels to urban subways, where its benefits in terms of safety, efficiency, and environmental impact are highly valued.

C. Importance of Understanding its Functionality and Implementation


To fully harness the potential of Tunnel Pipe Umbrella Technology, it is essential to grasp its inner workings and practical implications. By understanding its functionality and implementation nuances, stakeholders in the construction industry can make informed decisions and optimize their project outcomes.

II. Understanding Tunnel Pipe Umbrella Technology


A. What is Tunnel Pipe Umbrella Technology?


Tunnel Pipe Umbrella Technology, also known as the pipe umbrella system, is an advanced support method employed in tunnel construction to enhance safety and stability. It involves the installation of pipes or tubes in the tunnel face before excavation, creating a reinforced umbrella-like structure that supports the surrounding rock mass. This proactive approach minimizes the risk of collapses and deformations during tunneling operations.

B. How Does it Work?


The operation of Tunnel Pipe Umbrella Technology begins with the drilling of upwardly sloping holes on the top of the tunnel face. These holes serve as conduits for the insertion of supporting materials, typically steel pipes or tubes. Once in place, these pipes are grouted to reinforce the surrounding rock, providing a stable foundation for subsequent excavation activities. By distributing pressure and controlling deformations, the pipe umbrella system enhances the safety and efficiency of tunnel construction projects.

C. Key Components and Features


Common types of key components of the Tunnel Pipe Umbrella System include advanced small catheters, long tube sheds, and self-drilling hollow bolts. Each component serves a specific function in reinforcing the tunnel face and stabilizing the surrounding rock mass. Advanced small catheters, typically made of seamless steel pipe, are used for short-distance pre-support, while long tube sheds offer long-distance reinforcement in self-stabilizing and water-bearing strata. Self-drilling hollow bolts, equipped with drill bits and grouting capabilities, provide versatile anchoring solutions in challenging geological conditions.


III. Applicable Geological Conditions of Tunnel Pipe Umbrella Technology


Tunnel Pipe Umbrella Technology is particularly well-suited for unfavorable geological conditions, mainly referring to the areas of loose rock mass, weak and broken, expansion, karst, water, eccentric pressure, high ground stress, etc. By proactively addressing these challenges, the pipe umbrella system enhances safety and stability during tunnel excavation, mitigating the risks associated with unpredictable geological conditions.

IV. Materials Types of Tunnel Pipe Umbrella System


A. Advanced Small Catheter


The advanced small catheter is generally made of seamless steel pipe with a diameter of 38~50mm.

The advanced small duct is a basic type of advanced support for the pipe umbrella. It is a method of short-distance advanced pre-support. It is generally suitable for the formation where the face can be stabilized in a short time or the self-stabilizing ability of the surrounding rock is very low and there is little water. The exposed ends are often supported on the steel frame behind the excavation face to form a pre-support system together.

B. Long Tube Shed


Long tube sheds generally use seamless steel pipes with a diameter of 80-180mm and a wall thickness of 4-8mm.

The long tube shed is another basic type of advanced pre-support in the tunnel support. Compared with the small conduit grouting method, it is a long-distance advanced pre-support method. Due to the long advance distance and high rigidity, it is suitable for Self-stabilizing and water-bearing strata often form a pre-support system together with a steel frame, which has a better effect of controlling surface subsidence, better anti-seepage and water-stopping effect, higher construction technology requirements, and higher cost.

C. Self-Drilling Hollow Bolt


Self-drilling hollow bolt consists of a hollow bolt, connector, nut, drill bit, plate, and centralizer. It can combine drilling, grouting, and anchoring in one process. Self-drilling hollow bolts are safe, efficient, and convenient. Ideal for broken rocks, loose soils, and difficult-to-drill geology. It helps to ensure the anchoring effect under complex stratum conditions and achieve the best construction effect.

self drilling rock bolt system

Used in the pipe umbrella system, the self-drilling rock bolt has many advantages.

It combines drilling, grouting, and anchoring together, and is suitable for broken rock and conditions which are difficult to drill holes. Casing pipe is omitted in construction, which greatly improves construction efficiency.

The self-drilling rock bolt has a rich variety of drill bits, and the drill bit can be selected according to the properties of rock and soil, which can improve the drilling efficiency.

It can fill cracks, consolidate rock mass and soil layer through pressure grouting, and has good grouting spreading radius and reliable anchoring quality.

The hollow anchor bar can be cut arbitrarily and lengthened by the coupler. Therefore, the self-drilling anchor bolt is suitable for construction in a narrow space that large equipment cannot enter.

pipe umbrella in tunnel

V. Application Scenarios of Tunnel Pipe Umbrella


As an auxiliary method of tunnel construction, the pipe umbrella system has been rapidly developed in the construction of tunnels and underground structures. According to the existing construction cases, the pipe umbrella system is mainly used on the following occasions:

a. As a protection for tunnel construction under existing roads and railways;

b. As a protection for tunnels built in the ground and under important building structures on the ground;

c. As an auxiliary support method for large-section tunnel construction;

d. As an auxiliary method for the construction of the tunnel entrance section;

e. As an auxiliary method for breaking through a river bottom, seabed, fault fracture zone, collapsing surrounding rock, etc.;

f. Instead of construction beams or retaining plugs, it is used as an auxiliary method for other construction.


VI. Benefits and Advantages


A. Increased Safety and Stability in Construction Projects


By proactively reinforcing the tunnel face and stabilizing the surrounding rock mass, Tunnel Pipe Umbrella Technology reduces the risk of collapses, deformations, and other construction-related hazards. This enhances safety for workers and minimizes disruptions to project timelines.

B. Enhanced Efficiency and Cost-Effectiveness


The proactive support provided by the pipe umbrella system streamlines the tunnel construction process, reducing the need for extensive remedial measures and costly delays. By optimizing construction workflows and minimizing downtime, this technology improves project efficiency and cost-effectiveness.


C. Minimization of Environmental Impact


Tunnel Pipe Umbrella Technology minimizes environmental impact by reducing the disturbance to surrounding ecosystems and habitats. By mitigating the risks of collapses and surface subsidence, it helps preserve natural landscapes and ecosystems during tunnel construction activities.


D. Improved Resilience Against Natural Disasters and Adverse Weather Conditions


The reinforced structure created by Tunnel Pipe Umbrella Technology enhances the resilience of tunnels against natural disasters such as earthquakes, floods, and landslides. By providing a stable foundation and mitigating the risks of structural failure, it ensures the long-term safety and reliability of tunnel infrastructure in the face of adverse weather conditions and geological events.


VII. Conclusion and Analysis


If the tunnel is excavated with pipe umbrella support, it will be able to effectively control the settlement of the vault. Compared with the support without the pipe umbrella, the settlement of the tunnel vault is reduced by 77%, and the settlement of the tunnel vault with the pipe umbrella has a tendency to converge; During the support, the uplift value of the arch bottom is greatly reduced, which is 22%, indicating that the pipe umbrella in tunnel support can effectively control the deformation of the surrounding rock.

At present, the advanced pipe umbrella system technology has been widely used in underground projects such as highway tunnels, railway tunnels, urban subways, and underground passages as an auxiliary stabilization method for tunnel construction. The transportation and installation are flexible and convenient, so its use in mountain tunnels is more advantageous.

For reliable and high-performance self-drilling pipe roofing solutions, consider partnering with Sinorock. With a proven track record of innovation and expertise in geotechnical engineering, Sinorock offers a comprehensive range of self-drilling hollow bolts and anchoring systems designed to meet the unique needs of tunnel construction projects. Contact us today at sinorock@sinorockco.com to learn more about our products and services, and discover how we can support your tunneling endeavors with cutting-edge technology and unparalleled reliability.

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