Raft Foundation Lifting via Pressure Grouting Reinforcement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-rise buildings with raft foundations often experience uneven settlement due to insufficient foundation strength, leading to structural safety issues and the need for lifting and reinforcement, which existing methods fail to address effectively, especially in ultrahigh buildings with large load-bearing conditions and uncompacted soil strata.
Innovation Solution
A method involving arranging measuring points, forming reinforcement grouting, creating lifting holes, and drilling pile foundation holes to form a reinforced composite pile structure that supports the raft foundation, allowing for controlled lifting and prevention of re-settlement, using pressure grouting to lift the building while minimizing damage and ensuring stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pressure grouting is performed to lift the building, then the settlement problem is corrected, but the building structure may suffer damage
Solution Approach 1:
A reinforcement platform is formed by grouting before the lifting operation. This reinforcement platform, extending from the bottom surface of the raft foundation into the underlying soil layer, provides structural support and distributes lifting forces evenly, preventing damage to the building structure during the subsequent pressure grouting and lifting process
Solution Approach 2:
The reinforcement platform acts as a cushioning structure that absorbs and distributes the high pressures generated during pressure grouting. By providing this protective layer beforehand, the system prevents direct transmission of harmful forces to the building foundation and structure
2Manufacturing precision
If the building is lifted to correct settlement, then the inclination is corrected, but re-settlement may occur
Solution Approach 1:
The reinforcement platform is integrated with the raft foundation to form a combined reinforced structure. This merging of the reinforcement platform with the existing foundation system creates a unified load-bearing structure that prevents re-settlement by distributing building loads over a larger area and providing continuous support
Solution Approach 2:
The reinforcement platform creates a composite foundation structure combining the original raft foundation with grouted reinforcement materials extending into the soil. This composite structure leverages the strengths of both the concrete raft and the grouted soil reinforcement to provide enhanced stability and prevent future settlement
3Strength
If grouting reinforcement is performed, then foundation strength is improved, but the construction complexity increases
Solution Approach 1:
The grouting process serves multiple functions simultaneously: it forms the reinforcement platform for structural support, provides the lifting mechanism to correct settlement, and strengthens the underlying soil. This multi-functionality reduces the need for separate construction operations and simplifies the overall construction process
Solution Approach 2:
The method utilizes hydraulic pressure grouting to inject grout materials into the soil and form the reinforcement platform. This hydraulic approach enables controlled, efficient soil stabilization and reinforcement with minimal construction equipment and operations, simplifying the construction process while achieving significant foundation strengthening
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 provides good overall stability, controllable lifting speed and height, minimal damage, and prevents re-settlement by forming a reinforced pile plate structure that supports the building, effectively addressing the challenges of uneven settlement and structural safety in high-rise buildings.
Implementation Method 1
performing pressure grouting in the reinforcement grouting holes to form a continuous and complete reinforcement
Implementation Method 2
performing pressure grouting in the lifting holes simultaneously to lift the side to be lifted of the building
Implementation Method 3
drilling a plurality of pile foundation holes on the raft foundation, wherein a drill rod extends from the pile foundation holes into a soil layer below the bottom of the reinforcement
Implementation Method 4
in a drilling and/or retreating procedure, performing pressure grouting segment by segment and layer by layer to form a continuous pile foundation
Implementation Method 5
the pile foundation and the reinforcement are combined to form a pile plate reinforced structure for supporting the raft foundation and the building thereon together
Data Source
AI summary
Disclosed is a method for strengthening and lifting a high-rise building that has a raft foundation, comprising: arranging a plurality of measuring points at intervals around the outer contour of a building, and determining the side to be lifted of the building according to the elevation of the measuring points; distributing a plurality of reinforcement grouting holes perpendicular to a raft foundation at intervals within the range of the raft foundation, and using pressure grouting in the reinforcement grouting holes to form a reinforcement under the raft foundation; laying downwardly inclined lifting holes on the outer side of the raft foundation at two ends close to the side to be lifted of the building; and performing simultaneous pressure grouting in the lifting holes to lift the side to be lifted of the building.