As a leading Sydney construction company, our team is renowned for its ability to develop innovative solutions for complex design and construction challenges. The following case study exemplifies the unique methodologies employed by our team of highly qualified professionals, who consistently deliver exceptional results for our clients across Sydney.
The Project
Scape Lachlan is a two-tower student accommodation project consisting of an 18 and a 9-storey tower. This project is currently being built at Kensington Sydney.
The Construction Challenge – Completing deep construction of the two towers within the water table while maintaining a dry work area during the project’s construction.
What is the Water Table?
The water table is the water zone directly above the saturated zone (or zone of saturation). Above the water table, is the unsaturated zone, which contains soil, rock and air.
Challenges from High Water Table Construction Sites
High water tables can create several challenges in construction including:
- Instability: Saturated soils can be weak and unstable, posing a risk to foundations and structures.
- Excavation Issues: Water can seep into excavation sites, making it difficult to maintain the dry conditions necessary for construction.
- Increased Pressure: Water exerts hydrostatic pressure on building structures, which can cause damage or require additional structural support.
The Solution
There are two important parts:
- Design a retention system to retain the site’s deep excavation where lateral soil support is required. This system combines secant piles (interlocking concrete piles) with temporary ground anchors to provide additional stability and support during construction.
- Implementation of a dewatering system within the secant piles (dewatering needles).
Benefits of the Secant Pile Wall System
Safety: Prevents soil collapse and ensure the stability of excavation sites
- Water Control: Manages water infiltration and reduces hydrostatic pressure on the excavation and the structure.
- Structural Integrity: Provides a stable and secure environment for foundation and substructure construction.
Benefits of Dewatering System
- Dry Work Environment: Dewatering creates a drier work area, facilitating easier and safer construction operations. Workers can move freely, and equipment operates more efficiently in dry conditions.
- Reduced Risk of Flooding: Continuous removal of water prevents flooding within the excavation site, ensuring uninterrupted progress and reducing the risk of delays.
Steps with Implementation
Installation of Secant Pile Wall and temporary anchors
Step 1 – Site Assessment and Planning
- Conduct a thorough geotechnical investigation to understand soil conditions, water table levels and hydrostatic pressures.
- Design the appropriate shoring systems based on site-specific requirements and construction needs.
Step 2 – Installation of Secant Pile Wall and temporary anchors
- Mobilise equipment and materials to the site.
- Install secant piles and temporary anchors.
Step 3 – Dewatering Management
- Install dewatering systems such as pumps, needles, and water infiltration systems.
- Continuously monitor water levels and adjust dewatering efforts as needed to maintain dry and stable conditions.
Temporary wall anchors and dewatering needles
Step 4 – Commence excavation and construction.
- Begin excavation.
- Continue monitoring the stability of the shoring walls and water levels throughout the construction process.
- Install dewatering needles as excavation begins.
- As excavation progresses install dewatering needles deeper to lower the water table within the shoring wall.
- Continuous pumping and chemical treatment of pre-existing contaminated water from the high water table.
Step 5 – Ongoing monitoring and maintenance
- Regular inspection of the secant pile system for any signs of movement or distress
- Maintain dewatering systems and adjust as necessary to manage water levels.
Infinity Constructions: Your Trusted Sydney Construction Partner
At Infinity Constructions, we are more than just a Sydney construction company. We are a team of passionate professionals dedicated to exceeding your expectations on every project.
Sydney Construction Services Tailored to Your Needs:
- Pre-Construction: We offer comprehensive planning, feasibility studies, cost analysis, and value engineering to ensure your project starts on the right foot.
- Design & Construction (D&C): We provide a seamless single-source solution, managing the design and construction phases for optimal efficiency and streamlined communication.
- Construction Management: Leverage our expertise for expert project oversight, cost control, and schedule adherence.
- Sustainable Construction: We integrate environmentally friendly practices and materials throughout the construction process, minimizing your project’s environmental impact.
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Contact our experienced construction team today. We offer a free consultation to understand your vision and provide tailored solutions that meet your budget and schedule. Let Infinity Constructions transform your vision into a reality.
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