Concrete Slab Lifting via Subsurface Rod Distribution
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Solution Overview
Problem
Foundation slabs often settle due to soil conditions, causing damage to building structures, and existing lifting methods struggle to lift slabs effectively without causing further damage, especially due to the limited side-to-side strength of thin slabs.
Innovation Solution
A lifting system comprising a lifting apparatus with a first portion extending under the slab and a second portion coupled to piers, using lifting rods to restrict movement and distribute lifting forces, allowing for the slab to be lifted with minimal damage by supporting it from underneath.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If perimeter lifting is utilized to lift foundation slabs, then the slab can be raised to correct settling, but the slab frequently tends to settle in the center and may buckle or crack due to lack of support during lifting
Solution Approach 1:
The lifting apparatus divides the lifting function into multiple independent lifting points distributed across the slab surface. Each lifting point operates independently with its own lifting rod and support structure, allowing localized control of lifting forces to prevent buckling and maintain structural integrity during the lifting process
Solution Approach 2:
The apparatus incorporates preliminary support structures including base plates, lifting rods, and stabilization members that are positioned and secured to the slab before the actual lifting operation begins. This preliminary setup ensures uniform force distribution and prevents center settling during the lifting process
2Ease of operation
If thin foundation slabs (about four inches thick) are lifted using conventional methods, then lifting can be attempted, but the slabs lack sufficient side-to-side strength and are prone to damage
Solution Approach 1:
The lifting apparatus transitions from surface-level lifting to subsurface lifting by extending lifting rods through openings in the slab bottom and anchoring them to base plates positioned beneath the slab. This dimensional change allows lifting forces to be applied from underneath, distributing stress more effectively and preventing side-to-side damage in thin slabs
Solution Approach 2:
The apparatus introduces intermediary structural elements including base plates, lifting rods, and distribution beams that mediate between the lifting force and the thin slab. These intermediaries distribute concentrated lifting forces across larger areas, preventing stress concentration and structural damage to the thin slab material
3Area of stationary object
If multiple lift points are utilized around the perimeter of a settled building, then lifting coverage is improved, but the slab still lacks adequate support and may buckle in the middle
Solution Approach 1:
The lifting system segments the support structure into multiple independent lifting points distributed both at the perimeter and underneath the slab. This segmentation allows targeted support at critical locations including the center area, preventing buckling while maintaining comprehensive lifting coverage across the entire slab surface
Solution Approach 2:
The apparatus employs a nested configuration where lifting rods extend through openings in the slab bottom and are anchored to base plates positioned beneath. This nested arrangement allows the lifting structure to be contained within the slab's own footprint, providing centralized support underneath while maintaining perimeter lift points for comprehensive coverage
Data Source
AI summary
A lifting system utilizing a lifting apparatus for lifting a floor (e.g., a concrete slab) using the lifting apparatus to support a floor from under the floor during lifting. The lifting apparatus may have a first portion (e.g., an extension member and saddle) installed under a slab. Piers are driven into the ground through the first portion of the lifting apparatus. Thereafter, a second portion of the lifting apparatus is operatively coupled to the to the first portion and the uppermost pier. A lifting device (e.g., hydraulic ram) is operatively coupled to the lifting apparatus and/or the pier and is used to lift the slab.