Pressure Grouted Screw Pile With Integrated Grouting Module
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Solution Overview
Problem
Screw piles face limitations in load-carrying capacity due to reduced side friction and end-bearing capabilities, necessitating an enhancement in soil-pile interaction to increase overall pile capacity and performance.
Innovation Solution
A grouting module is integrated into the screw pile system, which creates an annular space around the pile shaft by injecting cementitious grout at elevated pressures, densifying the soil and increasing side friction and end-bearing capacity through the use of a check valve to maintain pressure and prevent backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If screw piles use smaller diameter pipe extensions, then installation equipment requirements are reduced and safety hazards are minimized, but side friction of the soil along the pile shaft decreases and overall pile load carrying capacity is affected
Solution Approach 1:
The patent places a grout injection system inside the hollow pile shaft, with grout outlets positioned along the shaft length. Grout is injected through the hollow shaft to form an annular grout layer between the shaft and surrounding soil, effectively nesting a functional system within the existing pile structure to enhance soil-pile interaction without increasing shaft diameter
Solution Approach 2:
The patent introduces cementitious grout as an intermediary material between the pile shaft and surrounding soil. This grout layer acts as a mediator that enhances side friction and end-bearing capacity by improving soil-pile interaction, allowing the smaller diameter shaft to achieve higher load carrying capacity through the intermediate grout layer
2Strength
If grout is injected at elevated pressures, then soil densification and side friction increase, but grout backflow and non-uniform distribution may occur
Solution Approach 1:
The patent incorporates a check valve in the grout injection system that provides automatic feedback control. The check valve allows grout to flow outward into the annular space but prevents backflow into the hollow shaft, maintaining elevated pressure during injection and ensuring uniform grout distribution without requiring complex active control systems
Solution Approach 2:
The patent divides the grout injection process into controlled segments along the pile shaft length, with multiple grout outlets positioned at different elevations. This segmentation allows grout to be injected in controlled portions along the shaft, ensuring uniform distribution and complete filling of the annular space without excessive pressure buildup that could cause backflow
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 pressure grouted screw pile system achieves increased load-carrying capacity and safety by minimizing equipment requirements and reducing installation time, while ensuring a uniform grout distribution and preventing neck formation, thus enhancing the structural integrity of the pile.
Implementation Method 1
injecting cementitious grout or other flowable material received from the upper hollow pile shaft through the axial bore extension into the annular space while the pile is advanced downward into a substrate
Implementation Method 2
injecting cementitious grout or other flowable material received from the upper hollow pile shaft through the axial bore extension into the annular space
Implementation Method 3
use of a check valve to maintain pressure and prevent backflow
Data Source
AI summary
A grouting module may include a lower surface configured for connection to a screw pile component, an upper surface configured for connection to an upper hollow pile shaft, a body disposed between the upper surface and the lower surface, and an axial bore through the upper surface and at least a portion of the body. The body may include a flange configured to create an annular space around the upper adapter and one or more flow injection conduits configured for injecting grout received from the upper hollow pile shaft through the axial bore extension into the annular space while the pile is advanced downward into a substrate. Once the final pile tip elevation is reached, the pile extensions above the grouting module are counter-rotated slightly to realign the ports in the grouting module from side to bottom discharge and allow post-grouting of the lead pile extension.