Tunnel Construction via Pull-In Anchorage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tunnel construction methods using prefabricated elements result in significant construction noise and vibrations due to the pressing process.
Innovation Solution
The method involves creating boreholes connecting start and end portals, inserting clamping elements, and using press cylinders to pull tunnel elements into the ground, with a flat material like sheet metal to reduce resistance and a lubricant to minimize noise and vibrations, allowing the end portal to serve as an anchorage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If prefabricated tunnel elements are pressed into the ground using conventional methods, then tunnel construction is achieved, but construction noise and vibrations increase significantly
Solution Approach 1:
The patent inverts the conventional pressing method by using pull-in forces instead of push forces. Clamping elements are anchored in boreholes at the target portal, and press cylinders at the starting portal pull the tunnel elements through the ground, reversing the direction of force application and eliminating the need for a press wall.
Solution Approach 2:
The patent introduces clamping elements as intermediaries that transfer force from the press cylinders to the tunnel elements. These clamping elements are inserted into boreholes and provide anchorage points, enabling the pull-in method while reducing direct contact forces that cause noise and vibrations.
2Stability of the object's composition
If a press wall is constructed to support conventional pressing methods, then structural stability is achieved, but construction costs and complexity increase
Solution Approach 1:
The patent extracts and eliminates the need for a press wall by using boreholes and clamping elements for anchorage. The target portal structure serves dual purposes as both the endpoint and the anchorage system, removing the additional structural complexity of a separate press wall.
3Ease of manufacture
If tunnel elements are pulled in without lubrication, then construction simplicity is maintained, but pull-in resistance increases due to friction with ground material
Solution Approach 1:
A flat material serves as an intermediary between the tunnel elements and the ground, creating a low-friction interface. This material is drawn in along with the tunnel elements and can have lubricant injected between it and the tunnel element surface, significantly reducing pull-in resistance without complicating the construction process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces construction noise and vibrations, lowers pull-in resistance, and eliminates the need for a press wall, resulting in cost savings and a more environmentally friendly, trenchless tunneling technique with minimal soil subsidence.
Implementation Method 1
clamping elements are inserted into which, by means of press cylinders, a driving part and tunnel elements are pulled into the ground
Implementation Method 2
It is also possible to inject a lubricant between the flat material and the tunnel element
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
In the method for constructing a tunnel extending from a starting portal (2) to a target portal (3) using tunnel elements (1), boreholes connecting the two portals (2, 3) are created, into which tensioning elements (10) are inserted. Using jacking cylinders (16), which are arranged on the side of the starting portal (2) and are operatively connected to the target portal (3) via the tensioning elements (10), a drive section (20) and subsequent tunnel elements (1) are pulled into the ground (5). The tunnel construction device comprises tensioning elements (10) designed to be inserted into boreholes connecting the two portals (2, 3), jacking cylinders (16), and a drive section (20).