Open Caisson Grouting for Sudden Subsidence Control in Soft Foundations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Open caissons in soft foundations are prone to sudden subsidence, which can cause safety hazards and damage to surrounding buildings due to friction resistance between the caisson and soft soil.
Innovation Solution
A method involving grouting to reinforce the foundation, pre-pressing sections with simulated loads, using convex blocks to increase friction, and adjusting parameters like cement slurry proportion and block size to stabilize the caisson during installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the open caisson is directly excavated for subsidence in soft foundation, then the subsidence process can proceed, but the open caisson may subside suddenly or more than once causing safety hazards
Solution Approach 1:
The patent applies preliminary action by pre-installing a foundation at the bottom of the open caisson before subsidence occurs. This foundation, constructed with cement slurry and reinforcement, prepares the soft soil in advance to bear the caisson's weight, preventing sudden subsidence during the excavation process.
Solution Approach 2:
The patent implements beforehand cushioning by creating a cushioning foundation layer at the caisson bottom using cement slurry and reinforcement structures. This foundation acts as a cushion that distributes and absorbs the impact forces, preventing sudden subsidence and ensuring stable, controlled settlement during construction.
2Strength
If grouting is carried out to reinforce the foundation, then the foundation strength is improved, but the construction process becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the foundation reinforcement into distinct components: grouting holes arranged in specific patterns, cement slurry injection, and separate reinforcement elements. This modular approach strengthens the foundation while making the construction process more manageable and less complex.
Solution Approach 2:
The patent implements local quality by applying grouting and reinforcement specifically at the foundation area where it is most needed - at the bottom of the open caisson. The grouting holes are strategically positioned to target weak soil areas, providing localized strength enhancement without unnecessarily complicating the entire construction process.
3Reliability
If pre-pressing is performed with load for 24 h, then the bearing capacity is tested and sudden subsidence is prevented, but the construction time is extended
Solution Approach 1:
The patent applies preliminary action by performing pre-pressing with load before the actual subsidence construction continues. This 24-hour pre-pressing test verifies the foundation's bearing capacity in advance, ensuring that subsequent subsidence proceeds smoothly without sudden failures, thereby saving time by preventing rework.
Solution Approach 2:
The patent implements feedback by using the results of the 24-hour pre-pressing test to inform subsequent construction decisions. If the foundation performs adequately during pre-pressing, construction can proceed confidently; if issues are detected, adjustments can be made before full-scale subsidence, preventing time-consuming corrections later.
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
Prevents sudden subsidence, ensures safe and smooth construction, reduces construction risks, and avoids potential safety hazards by stabilizing the caisson in soft soil environments.
Implementation Method 1
In S3, cement slurry is injected into the grouting holes, and grouting is carried out to form the foundation of the open caisson
Implementation Method 2
by disposing the convex blocks, excessive impact force brought to the bottom section by too fast subsidence of the section may be avoided
Data Source
AI summary
A method for preventing sudden subsidence of an open caisson in a soft foundation includes the following steps: a position of the open caisson is determined; grouting is carried out to reinforce a foundation of the open caisson; an open caisson manufacturing site is leveled; sections of the open caisson are manufactured and installed; the step of sections of the open caisson are manufactured and installed is repeated until all the sections are manufactured and the open caisson subsides in place as a whole.