Rail Bed Subgrade Grout Inclusions With Minimal Ballast Removal
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Solution Overview
Problem
Current methods for railroad track maintenance and repair are time-consuming, costly, and do not effectively target subgrade and subsoil stabilization, leading to temporary solutions and long-term destabilization of rail beds.
Innovation Solution
A system and method involving a rail-mounted drilling rig that injects a slurry mixture of cement grout and soil into the subgrade and subsoil to create cylindrical inclusions and fill ballast pockets, stabilizing the subgrade and subsoil, with equipment that is self-sufficient and minimally invasive.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lateral access to the rail bed is created by undercutting and removing ballast layers, then equipment can access the subgrade for repair, but significant removal of rail bed layers is required and the solution is only temporary
Solution Approach 1:
The patent extracts only the necessary portion of ballast material to create access holes, rather than removing entire ballast layers. The drilling rig creates localized access points through the ballast to reach the subgrade, minimizing material removal while enabling repair equipment to access and treat the subgrade soil.
Solution Approach 2:
The patent introduces a drilling rig as an intermediary tool that creates access holes through the ballast layer without requiring manual removal of ballast. This intermediary device enables precise, minimal-invasive access to the subgrade while preserving the overall ballast structure.
2Ease of manufacture
If traditional maintenance equipment is used with loading and unloading processes, then repair work can be performed, but the process is time-consuming and increases railway downtime
Solution Approach 1:
The drilling rig is designed as a multi-functional unit that combines drilling, soil sampling, and grout injection capabilities in a single rail-mounted system. This universal equipment eliminates the need for multiple separate operations and equipment transfers, significantly reducing maintenance time while maintaining comprehensive repair capability.
Solution Approach 2:
The rail-mounted drilling rig is self-sufficient, carrying its own drilling equipment, grout storage, and injection systems. The equipment serves itself by performing all repair operations from a single platform without requiring external support equipment or repeated loading/unloading cycles.
3Strength
If subgrade stabilization is attempted with temporary packing methods, then immediate support is provided, but long-term destabilization occurs due to subgrade failure
Solution Approach 1:
The patent performs preliminary soil stabilization by injecting grout into the subgrade before restoring the ballast layer. This preliminary action strengthens the subgrade soil in advance, preventing future settlement and ensuring long-term reliability of the rail bed structure.
Solution Approach 2:
The patent changes the physical and chemical parameters of the subgrade soil by injecting cementitious grout that alters the soil's strength, density, and compressibility characteristics. This parameter transformation converts weak, compressible subgrade soil into a stable, load-bearing foundation that prevents long-term destabilization.
4Ease of operation
If extensive ballast removal is performed for access, then subgrade repair is possible, but additional ballast cleaning or replacement is required after repair
Solution Approach 1:
The patent extracts minimal ballast material only where necessary to create small access holes for drilling, rather than removing large sections of ballast. This selective extraction preserves the majority of the ballast structure, eliminating the need for extensive post-repair ballast cleaning or replacement operations.
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 provides efficient, cost-effective, and long-term stabilization of subgrade and subsoil, reducing maintenance costs and minimizing railway downtime, while avoiding the need for additional ballast cleaning or replacement.
Implementation Method 1
The drill head mixes the soil and grout to form stabilized soil-cement inclusions
Implementation Method 2
A system and method involving a rail-mounted drilling rig that injects a slurry mixture of cement grout and soil into the subgrade and subsoil to create cylindrical inclusions
Data Source
AI summary
The invention is a system and method for repairing, improving, and stabilizing subgrade and subsoil/natural ground layers of a rail bed generally consisting of softer soils. One embodiment includes a method of installing subsurface inclusions and ballast fills comprising injected slurry mixtures of stabilizing material such as cement grout mixed with in situ soil. Another embodiment includes a system of installed ground inclusions and ballast fills. Another embodiment includes an integrated system of equipment for emplacing the system of inclusions and ballast fills.