Webless Rail Design for Shallow Track Slab Construction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The construction of tram tracks in urban areas is hindered by the need to bury slabs to accommodate existing underground networks, leading to costly and inconvenient excavation, and there is a risk of stray currents causing corrosion due to inadequate electrical insulation and connection between rails and the ground.

Innovation Solution

The use of ultra-low rails without a web, allowing for shallower notches and a thinner track slab, along with a mobile jig for precise rail placement and a polyurethane-based resin coating to prevent stray currents and reduce noise and vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the thickness of track slabs is reduced to minimize network deviation work, then construction cost and inconvenience are reduced, but the resistance and structural integrity of the slabs may be compromised

Engineering Contradiction:
Improveconstruction cost and inconvenienceVSAvoidslab resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent employs composite material structures in the track slab design, combining different materials with complementary properties to achieve both reduced thickness and maintained strength. The composite structure allows for optimized load distribution and mechanical performance despite the reduced overall thickness of the slab.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality enhancement by reinforcing specific critical areas of the track slab rather than uniformly increasing thickness throughout. This targeted reinforcement strategy maintains structural integrity at load-bearing locations while keeping the overall slab thickness reduced, thereby minimizing network deviation work.

Inventive Principle:
Principle #3Local quality

2Length of stationary object

If rails are located in the ground to reduce structure thickness, then overall structure thickness is reduced, but stray currents may escape from rails and cause corrosion to networks

Engineering Contradiction:
Improvestructure thicknessVSAvoidcorrosion from stray currents
Core Design Contradiction:
Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary insulating layer or coating between the rails and the surrounding ground/networks. This intermediary material serves as an electrical barrier that prevents stray currents from escaping the rails and corroding underground networks, while allowing the rails to remain at ground level for reduced structure thickness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates an electrically inert environment around the rails through insulating materials or coatings that prevent electrical interaction between the rails and the ground. This inert environment blocks the harmful stray current paths that would otherwise lead to corrosion of underground networks.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Strength

If conventional rails with web are used, then structural strength is maintained, but notch depth and track slab thickness must be increased

Engineering Contradiction:
Improverail structural strengthVSAvoidnotch depth and slab thickness
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The patent extracts or removes the web component from conventional rail designs, retaining only the essential load-bearing elements (head and foot). This extraction eliminates the need for deep notches to accommodate the web, thereby reducing notch depth and track slab thickness while maintaining sufficient structural strength through optimized head and foot geometry.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the geometric parameters of the rail profile by eliminating the web and adjusting the dimensions of the head and foot sections. This parameter change allows for shallower notches and thinner slabs while maintaining the rail's load-bearing capacity through optimized distribution of material in the remaining sections.

Inventive Principle:
Principle #35Parameter changes

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 the overall structure thickness by 15-20% and minimizes network deviation work while ensuring effective electrical insulation and reducing the cost of insulating products.

Implementation Method 1

it is necessary to ensure both a good electrical connection between rails and good electrical insulation of the rails relative to the ground

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

a polyurethane-based resin coating to prevent stray currents and reduce noise and vibration

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2850249B1Method for constructing a railway track
Publication Date: 2018.11.07 ETF
  • EP2850249B1 patent drawingFigure 1~2A
  • EP2850249B1 patent drawingFigure 2B~3

AI summary

The invention also relates to a method for constructing a railway track (V1), comprising the steps consisting in: pouring a track slab (3) on a foundation slab (2); making two parallel longitudinal notches (5a, 5b) in each track, from the upper surface (3a) of the track slab; and securing a rail (11a, 11b) in each notch, each rail comprising a rail base (12) topped with a rail head (13) and a flap (14), said rail head and flap defining therebetween a groove (15), said rails (11a, 11b) not including webs. Advantageously, the height of the rails is less than or equal to half of the width.