Trenchless Tunneling System Pull-In Mechanism

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Solution Overview

Problem

Existing tunneling systems for trenchless construction are inefficient in terms of cost and effort, with significant noise, vibrations, and subsidence issues due to the pressing of tunnel elements into the ground, which complicates soil removal and material handling.

Innovation Solution

A modular tunneling system incorporating a full-cut milling machine with individually controllable drilling and milling drums, electric motors for reduced noise and vibration, and a conveyor belt system for efficient soil removal, allowing for the pulling of tunnel elements with minimal subsidence and easy expansion to handle obstacles, while using electric motors to prevent soil contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If tunnel elements are pressed into the ground using press cylinders, then tunnel construction can be achieved, but noise, vibrations, and subsidence occur

Engineering Contradiction:
Improvetunnel construction efficiencyVSAvoidnoise and vibrations
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional pressing method by using pull-in devices instead. Tunnel elements are pulled into the ground through threaded tie rods and press cylinders that exert tensile force rather than compressive force. This inversion eliminates the harmful noise and vibrations associated with traditional pressing methods while achieving the same construction objective.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of manufacture

If tunnel elements are pressed into the ground, then tunnel construction can be achieved, but subsidence occurs complicating soil removal

Engineering Contradiction:
Improvetunnel construction efficiencyVSAvoidground stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

By inverting the construction method from pressing to pulling, the patent prevents ground subsidence that complicates soil removal. The pull-in method maintains ground stability while achieving tunnel element installation, allowing for easier and more reliable soil removal operations.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of manufacture

If conventional pressing methods are used, then tunnel elements can be installed, but cost and effort efficiency are reduced

Engineering Contradiction:
Improvetunnel construction capabilityVSAvoidcost and effort efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent achieves superior cost and effort efficiency by inverting the construction approach. The pull-in method using threaded tie rods and controlled press cylinders reduces the effort required compared to conventional pressing, while the ability to pull elements into position provides better cost-effectiveness overall.

Inventive Principle:
Principle #13The other way round (Inversion)

4Productivity

If milling drums are made solid for full cut milling, then soil removal is efficient, but the machine cannot handle obstacles like boulders

Engineering Contradiction:
Improvesoil removal efficiencyVSAvoidobstacle handling capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The milling drums are segmented into multiple removable drum parts arranged coaxially. This segmentation allows individual drum parts to be removed when obstacles like boulders are encountered, enabling the machine to handle diverse ground conditions. The modular design maintains full cut milling capability for normal soil removal while providing adaptability for obstacle removal.

Inventive Principle:
Principle #1Segmentation

5Power

If hydraulic motors are used for driving milling drums, then power transmission is effective, but soil contamination occurs

Engineering Contradiction:
Improvedrive power transmissionVSAvoidsoil contamination
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent replaces hydraulic motors with electric motors with screw drives for the milling drums. This substitution eliminates soil contamination from hydraulic fluid while maintaining effective power transmission through the electric motor and screw mechanism. The mechanical screw drive provides sufficient torque for full cut milling without the contamination risks of hydraulic systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The system achieves cost-efficient and effort-efficient tunnel construction with reduced noise, vibrations, and subsidence, enabling continuous operation with minimal disruption and efficient soil removal, allowing for real-time correction of any subsidence during construction.

Implementation Method 1

Several press cylinders or electric motors with screw drives are arranged on the side of the start portal and are in operative connection with the destination portal via the clamping elements. The tunnel elements are pulled into the ground by means of the press cylinders or electric motors with screw drives.

Methodology Applied
Scientific EffectMechanical Force: Force

Implementation Method 2

a milling machine, preferably a full-cut milling machine, is arranged on the system in operative connection with the first tunnel element in the advance direction of the system. The drilling milling drums for removing soil

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 3

electric motors with screw drives are arranged on the side of the start portal and are in operative connection with the destination portal via the clamping elements. Each of the boring milling drums has a drive assigned to it.

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 4

The milled-off material is conveyed by the rollers to the rear into the interior of the tunneling system, where it falls down onto a conveyor belt system and is conveyed by this to the exterior for removal.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3133238B1Tunnel construction system
Publication Date: 2020.10.07 ZEHMEI AG
  • EP3133238B1 patent drawingFigure 1~2
  • EP3133238B1 patent drawingFigure 3a~3b
  • EP3133238B1 patent drawingFigure 4a

AI summary

A system (T) for trenchless tunnel construction by pulling several tunnel elements (5) into place is disclosed, comprising a starting portal (1) and a receiving portal (2) connected by tension rods (3) arranged in boreholes. The boreholes extend through the soil (E) outside the cross-sectional area of ​​the tunnel elements (5) to be pulled in. Several electric motors with threaded drives (11) are arranged on the side of the starting portal (1) and are operatively connected to the receiving portal (2) via the tension rods (3). The tunnel elements (5) are pulled into the soil (E) by means of the electric motors with threaded drives (11). The receiving portal (2) can be used as an anchor during tunnel construction. This means that the tunnel elements (5) are pulled in rather than pressed in, thus reducing construction noise and vibrations, among other things.A milling machine (8), preferably a full-cut milling machine, is arranged in operative connection to the first tunnel element (5). It has several stacked drilling and milling drums (20), each consisting of several individual drums and movable as a whole in a laterally oscillating manner.