Low-Water Acrylate Sealing for Tunnel Segmental Lining
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Solution Overview
Problem
Tunnel structures constructed using segment construction methods face challenges in geologically problematic environments, such as water-reactive subsoils, where mortar suspensions can cause damage due to water reactions, leading to instability and leakage.
Innovation Solution
A method involving the use of a low-water acrylate composition, with less than 10% water by weight, injected into the annular gap between the cavity and segment components, which is free-radically curable and includes specific (meth)acrylate monomers and crosslinkers to fill and seal the gap without cement, ensuring stability and water resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If mortar suspension is used to fill the annular gap, then the segment components are stabilized and embedded in the loosened soil, but water reactions in water-reactive subsoil cause damage to the tunnel structure
Solution Approach 1:
The patent changes the chemical composition parameters of the filling material from traditional mortar suspension (water-based, cementitious) to an acrylate composition with less than 10% water content that is free-radically curable. This parameter change eliminates the water-cement reactions that cause damage in water-reactive subsoil while maintaining the stabilizing function of the annular gap filling.
Solution Approach 2:
The patent employs a low-water acrylate composition that cures rapidly through free-radical polymerization to form a durable seal. The composition is designed to be injected and cured in situ, replacing the need for traditional mortar that requires prolonged curing time and water content, thus providing a more efficient and adaptable solution for problematic ground conditions.
2Reliability
If traditional mortar suspension is used, then the annular gap is filled, but cement-based materials cannot effectively seal fissures and cavities in surrounding rock in water-reactive environments
Solution Approach 1:
The patent fundamentally changes the chemical parameters of the sealing material by using an acrylate composition with less than 10% water content that cures via free-radical mechanism rather than cement hydration. This enables effective sealing in water-reactive subsoil and fissured rock where traditional mortar would react adversely with the groundwater and fail to provide reliable sealing.
Solution Approach 2:
The acrylate composition functions as a composite sealing material that combines low-water content formulation with free-radical curable polymers to achieve both water resistance and effective fissure sealing in challenging geological conditions, overcoming the limitations of single-component cement-based mortars.
3Ease of manufacture
If mortar suspension is injected under pressure, then the annular gap is filled and segments are embedded, but the water content in the mortar leads to damaging reactions with water-reactive subsoil
Solution Approach 1:
The patent maintains the ease of injection and gap filling by using a fluid acrylate composition that can be pumped under pressure similar to mortar suspension. However, the critical parameter change is reducing water content to less than 10% and using free-radical curable acrylate monomers instead of cementitious binders, thereby eliminating water reactions with water-reactive subsoil while preserving the injectability and embedding function.
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 method effectively seals and stabilizes tunnel structures in challenging geological conditions, preventing water ingress and maintaining structural integrity by using a low-water acrylate composition that cures to form a durable, water-resistant seal.
Implementation Method 1
the acrylate composition is a free-radically curable acrylate composition
Data Source
AI summary
The present invention relates to a method for constructing a tunnel structure, in particular a road tunnel, using segmental lining, in which segmental lining components are assembled in a machine-produced cavity bore through the subsoil to form a closed lining, and bulk material is introduced into the space between the inner wall of the cavity and the outer walls of the segmental lining components, in particular the space is filled with bulk material. In addition to introducing bulk material into the space, an acrylate composition is introduced to fill the space, wherein the acrylate composition contains less than 10% water by weight, based on the total weight of the acrylate composition, and the acrylate composition is a radically curable acrylate composition.