Ground Foundation with Expellable Steel Wires for Pull-Out Resistance
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Solution Overview
Problem
Existing ground dowels, such as screw-in and hammer-in types, fail to provide sufficient pull-out resistance, especially in softer soils, and egg-hammer dowels yield excessively under vertical load, making them unsuitable for anchoring buildings or structures.
Innovation Solution
A method involving a ground foundation with a ground dowel and axially arranged steel wires that form a concrete base by displacing soft concrete mortar into the soil, creating a rigid connection and increasing extraction force without slippage, using a process that involves drilling, filling with concrete, and driving in the dowel with expellable steel wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional ground dowels (screw-in or hammer-in) are used, then installation is simple, but pull-out resistance is insufficient in softer soils
Solution Approach 1:
The ground foundation combines multiple materials and components: a metal ground dowel, expellable steel wires, and injected mortar to form a composite anchoring system. The steel wires embed into the surrounding soil while the mortar fills gaps and bonds the components, creating a composite structure that achieves high pull-out resistance without complicating installation.
2Strength
If egg-hammer dowels with steel wires are used, then pull-out resistance is improved, but the wires stretch under vertical load causing the dowel to lift out by several centimeters
Solution Approach 1:
The steel wires are pre-loaded in a compressed state within the ground anchor before installation. When the ground dowel is driven into the ground, the wires are forced outward against the soil in advance, creating immediate anchoring resistance. This preliminary action prevents the wires from stretching under subsequent vertical loads, eliminating the lifting problem.
Solution Approach 2:
The invention changes the stress state parameter of the steel wires from a relaxed state to a pre-compressed state. By forcing the wires outward against the soil during installation, the wires are held in a compressed condition that prevents stretching under load, thereby maintaining anchoring stability.
3Strength
If the hole is filled completely with concrete mortar before inserting the dowel, then anchoring is improved, but the dowel cannot be driven in sufficiently deep
Solution Approach 1:
Instead of filling the hole completely with mortar, the invention uses partial filling (approximately 1/2 to 3/4 of the hole depth). This partial action provides sufficient mortar for wire embedding and anchoring strength while leaving enough space for the dowel to be driven to the required depth without excessive resistance.
Solution Approach 2:
The mortar is placed in the hole before the dowel installation as a preliminary preparation. This allows the mortar to be positioned optimally for anchoring purposes while not interfering with the subsequent driving-in process, as the dowel is inserted and driven into the partially filled hole.
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
This method achieves a simple and secure ground foundation with enhanced anchoring and increased pull-out resistance, requiring minimal additional work and tools, ensuring a stable connection without slippage.
Implementation Method 1
the steel wires are expelled, emerge from the ground anchor tip, penetrate helically into the concrete mortar soil mass
Implementation Method 2
The concrete mass in the hole is displaced by the dowel tube and pressed laterally and downwards into the ground at the bottom of the hole, with the concrete mass in turn displacing and/or penetrating the ground and forming a balloon-shaped extension
Implementation Method 3
After the concrete base has solidified or completely dried out, the ground foundation can be loaded to prevent it from being pulled out
Data Source
Figure 1~3
Figure 4~7
AI summary
In a method for installing a ground foundation into the ground, consisting of a ground anchor (5) and an axially arranged and underside-projecting ground anchor (11) with extrudable steel wires (14), a hole (18) with a slightly smaller cross-section but greater depth than that of the ground anchor of the ground foundation is drilled into the ground. The hole is then preferably filled to a height of 2/3 with soft concrete mortar (20), and the ground foundation (1) is inserted and driven in to the specified depth. The displaced concrete mass penetrates the ground and forms a balloon-shaped extension (28) at the end of the anchor, forming a concrete base (15). A drive mandrel (23) is then inserted into the ground anchor and driven in, causing its steel wires to be driven out in a spiral pattern and engage in the soft concrete mass of the base.The resulting ground foundation (1) has, in its state when inserted into the ground, a ground anchor (5) with a balloon-shaped concrete base (15) at its lower part, in which steel wires (14) driven out of its tip are anchored.