Underpinning Pile Assembly with Nested Steel Pipe and Concrete Segments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing underpinning pile assemblies face challenges in achieving proper depth in hard or dense soils, and steel components are prone to corrosion due to exposure to moisture and oxygen, leading to instability and reduced effectiveness over time.
Innovation Solution
The underpinning pile assembly consists of steel pipe segments with a key member system for vertical alignment and a transition member with a collar and flange to support concrete pile segments, allowing for deeper penetration into dense soils while minimizing exposure to moisture and oxygen, thus reducing corrosion and torque on the foundation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If steel pipe segments are used for underpinning piles, then the piles can penetrate deeper into dense soils, but the steel components are exposed to moisture and oxygen causing corrosion
Solution Approach 1:
The steel pipe segments are nested within concrete pile segments, with the steel pipes positioned inside the concrete segments. This nesting arrangement allows the steel pipes to achieve deep penetration into dense soils while the concrete provides a protective environment that minimizes exposure to moisture and oxygen, thereby reducing corrosion.
Solution Approach 2:
The underpinning pile assembly combines steel pipe segments with concrete pile segments to create a composite structure. The steel pipes provide high strength for penetration into dense soils, while the concrete material provides corrosion protection by limiting exposure to moisture and oxygen, thus resolving the contradiction between penetration depth and corrosion resistance.
2Length of moving object
If steel pipe segments are driven into dense soils, then deeper penetration is achieved, but torque is applied to the foundation causing instability
Solution Approach 1:
The composite structure of steel pipes within concrete segments distributes the driving forces and torques more effectively. The concrete material, being more resistant to torsional stresses, protects the foundation from excessive torque while allowing the steel pipes to achieve the necessary penetration depth into dense soils.
3Ease of operation
If precast concrete segments are stacked vertically, then installation with minimal clearance is possible, but misalignment of segments occurs
Solution Approach 1:
The steel pipe segments are nested within the concrete pile segments, providing internal guidance and alignment references. This nesting arrangement helps maintain vertical alignment during installation while still allowing the compact stacked configuration that requires minimal clearance between segments.
4Ease of manufacture
If unreinforced concrete segments are used, then construction is simplified, but permanent separation or breakage occurs in clay soils with high shrink-swell potential
Solution Approach 1:
The combination of steel pipes and concrete segments creates a composite structure where the steel provides tensile reinforcement. This reinforcement prevents permanent separation at segment joints and breakage at midpoints in clay soils with high shrink-swell potential, while maintaining the simplicity of using precast concrete segments.
Data Source
AI summary
An underpinning pile assembly for supporting a structure upon the earth has at least one steel pipe, at least one concrete pile segment positioned above the steel pipe, and a transition member interposed between the steel pipe and the concrete pile such that the load of the concrete pile is supported by the steel pipe. The steel pipe includes a plurality of steel pipe segments extending in end-to-end relationship in generally vertical alignment. A key member is received in slots formed in the respective ends of the first and second segments. The plurality of concrete pile segments includes a strand affixed in holes formed through the plurality of concrete pile segments.