ASAP Piling — Basement Retention Specialist
Contiguous Piling Melbourne — Basement Retention Specialists Since 2001
Contiguous piling creates an earth retention wall by drilling a closely-spaced row of bored piles before excavation begins, forming a near-continuous barrier that holds the surrounding ground in place. ASAP Piling has constructed contiguous pile walls for residential basements, townhouse developments, and commercial buildings across Melbourne since 2001.
What Is Contiguous Piling?
A contiguous pile wall is a row of bored piles drilled close together — not touching, but near enough to act as a continuous barrier. The piles go into the ground before any excavation begins. Once the wall is in place and the capping beam is complete, the dig happens safely inside the protected perimeter.
Contiguous pile walls are the standard method for basement construction in Melbourne. They are used wherever you need to excavate below ground and the surrounding soil must be held back during and after the dig — protecting neighbouring properties, roads, and existing structures throughout the construction process.
The Installation Process
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Set-Out from Engineer's Drawings
The pile positions are set out from the engineer's drawings before work begins. Pile diameter, spacing, depth, and reinforcement are all specified by the structural engineer based on the geotechnical report and excavation depth.
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Primary Pile Installation
Primary piles are drilled and filled with reinforced concrete first. Every second pile position is completed to avoid the auger cutting into fresh concrete in an adjacent pile. Primary piles are given time to gain initial strength before secondary piles are drilled.
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Secondary Pile Installation
Secondary piles are drilled between the primary piles to complete the wall. The auger is positioned to maintain the design gap between adjacent pile surfaces. Reinforcement and concrete placement follows the same process.
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Capping Beam Construction
A capping beam is cast along the top of all pile heads to tie the wall together as a single structure. The capping beam transfers lateral earth pressure loads into the pile wall and provides the connection point for the basement slab and any temporary prop or permanent anchor system.
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Excavation Inside the Wall
Excavation then proceeds safely inside the completed wall. As excavation depth increases, temporary props or permanent ground anchors may be installed at design levels specified by the structural engineer.
Applications in Melbourne
Residential Basements: Single and double basement construction beneath new homes and townhouses in Melbourne's inner suburbs. Contiguous piling allows the basement perimeter to be constructed and excavated without disturbing adjacent properties.
Townhouse Underground Car Parks: Multi-unit developments with basement car parking. Contiguous pile walls define the perimeter of the basement level before the building structure above is constructed.
Commercial Basement Structures: Office, retail, and mixed-use buildings requiring one or more basement levels. Contiguous piling provides a permanent structural basement wall that can be designed as part of the building's overall structural system.
Earth Retention Adjacent to Existing Structures: Retaining walls on sloping blocks and sites where deep excavation adjacent to existing buildings or property boundaries requires a structural permanent wall. Rotary drilling means zero impact vibration to neighbouring structures.
Available Specifications
Contiguous Piling vs Sheet Piling
| Factor | Contiguous Pile Wall | Sheet Pile Wall |
|---|---|---|
| Method | Drilled reinforced concrete piles | Driven or pressed interlocking steel sections |
| Water Exclusion | No — gaps between piles allow groundwater through | Yes — interlocking sections exclude water |
| Best Use | Permanent basement walls, residential and commercial | High-groundwater sites, cofferdams, waterfront |
| Vibration | Zero — rotary drilling only | Vibratory hammer installation |
| Finish | Concrete wall face after excavation | Steel wall face |
| Melbourne Residential Basement | Standard method | Less common for residential |
Frequently Asked Questions
Enquire About Contiguous Piling
Call Nick on 0499 888 799 with your engineer's drawings and soil report.
Related Services
Contiguous pile walls are always followed by a capping beam. For water-excluding walls, consider sheet piling. For individual foundation elements, see bored piers.