Water-Soluble Soil Sample Mould for Triaxial Testing
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Solution Overview
Problem
Existing methods struggle to prepare non-self supporting soils, such as soft clays and sediments, for mechanical testing due to their fragile nature and inability to maintain shape during transportation and testing, leading to inaccurate laboratory results.
Innovation Solution
A triaxial testing method using a water-soluble PVA casing molded by 3D printing, which surrounds the soil sample with a latex membrane, allowing the casing to dissolve under low water pressure while maintaining the sample's shape and preventing water escape, enabling tests like saturation, consolidation, and shearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If non-self supporting soil samples are prepared using conventional methods, then the samples can be collected, but the samples cannot maintain their shape during transportation and testing
Solution Approach 1:
The patent uses a water-soluble PVA casing that dissolves during the testing process. This disposable casing maintains the soil sample's shape during transportation and preparation, then dissolves away during saturation and consolidation tests, allowing accurate testing without sample disturbance while eliminating the need for complex sample retrieval mechanisms.
Solution Approach 2:
The water-soluble PVA casing acts as an intermediary between the soil sample and the testing environment. It provides temporary structural support during sample preparation and transportation, then dissolves to allow direct contact between the soil sample and water during saturation and consolidation tests, ensuring accurate mechanical property measurements.
2Ease of manufacture
If water is introduced to dissolve the casing, then the sample can be prepared for testing, but water may escape through the pressure system
Solution Approach 1:
The patent employs a latex membrane as a flexible sealing barrier that conforms to the pressure vessel walls and prevents water escape during the dissolution process. This thin film creates an effective seal around the sample and casing assembly, allowing water to be introduced for dissolving the PVA casing without loss through the pressure system.
3Productivity
If traditional sampling devices are used, then soil samples can be collected, but the samples cannot be prepared for mechanical property testing
Solution Approach 1:
The patent combines the soil sampling function with the sample preparation and testing containment functions into a single integrated system. The PVA casing serves as both the sample collection container and the testing vessel, eliminating the need for separate sampling devices and preparation steps, thereby enabling both efficient collection and direct mechanical property testing.
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 maintains soil shape and prevents water loss during testing, allowing accurate determination of consolidation and shear properties, reducing hardware costs and simplifying the testing process for non-self supporting soils.
Implementation Method 1
a water-soluble PVA casing molded by 3D printing, which surrounds the soil sample with a latex membrane, allowing the casing to dissolve under low water pressure
Implementation Method 2
which surrounds the soil sample with a latex membrane, allowing the casing to dissolve under low water pressure while maintaining the sample's shape and preventing water escape
Data Source
Figure 1
Figure 2a)~2h)
Figure 3~4
AI summary
Invention relates to a mould for preparing non-self supporting soil sample for testing its mechanical properties. Mould comprises a mould base 6 having water inlet 9 and a pressure unit inlet 8 on which a lower sample base 10a that comprises a porous stone is placed, to said porous stone a filter paper and a latex membrane 4 are attached by means of O-rings 7a, wherein a base mount 3 surrounds a porous stone and a lower part of the water-soluble casing 1, while water-soluble casing 1 is placed between a latex membrane 4 and a temporary separable mould 5 on top of which a latex membrane 4 that contains the soil sample P is wrapped around, wherein on the sample P, an upper sample base is placed, that comprises in order: a filter paper, porous stone and on top of which an cover 10b with O-rings 7b is placed. Additionally the invention relates to a method of preparing non-self supporting soil samples for testing its mechanical properties, wherein a method comprises steps in which in the above described mould, that has an upper sample base and mould cover 10b detached in which: soil sample P is placed in the latex membrane by generating a vacuum by means of pressure unit attached to a mould base after all of the sample has been placed into a latex membrane, air is eliminated from the bottom sample base by introducing distilled water via water inlet and then the sample P is closed in a mould by putting upper sample base and cover on top of it separable mould is removed sample in the remaining of the mould is inserted into triaxial chamber water is introduced to the remaining of the mould via water inlet in such a manner that drainage of water is prevented, until soluble casing is dissolved, wherein during dissolving of a water-soluble casing, water escape from the pressure unit is prevented.