CONTIGUOUS RETAINING WALL

OVERVIEW

Contiguous walls are a widely used type of retaining wall designed to support and stabilize the ground in areas where soil retention is crucial. These walls are particularly effective in applications such as building basements, creating shafts for underground structures, and supporting transportation infrastructure like bridge abutments and tunnel walls. Contiguous walls consist of closely spaced vertical piles, which work together to prevent soil movement and maintain the integrity of the excavation.

CONSTRUCTION

The construction of contiguous walls involves drilling a series of vertical piles utilizing various piling technique such as CFA,SFA and Rotary. typically made of reinforced concrete, at regular intervals along the proposed wall line. The close spacing of these piles creates a continuous barrier that retains the soil behind it. This method is especially useful in urban environments where space is limited, and adjacent structures or underground utilities need to be protected during excavation.

What are the advantages of Contiguous Piled Walls?

More cost effective than diaphragm walls

Greater flexibility in terms of geometry

Individual piles pile can provide both lateral support and bearing capacity

Piles can be installed within challenging ground conditions using rotary techniques

Suited to city centre to support excavations within congested sites

The design of continuous walls considers adjacent structures and utilities

DESIGN

Our in-house design team is skilled in optimizing the structural design and construction sequence of contiguous walls to meet the specific requirements of each project. By carefully analyzing factors such as soil conditions, load-bearing needs, and site constraints, we ensure that the contiguous wall system is both effective and efficient. This approach allows us to deliver a reliable solution that ensures the stability and success of the project

SECANT RETAINING WALL

OVERVIEW

Secant walls are not only effective in supporting and stabilizing the ground but also in retaining water, making them an ideal solution for projects where groundwater control is essential. These walls are particularly advantageous in environments with high water tables or where the excavation needs to remain dry, such as in the construction of deep basements, underground parking structures, and shafts for tunnels or utility installations. By forming a continuous and impermeable barrier, secant walls prevent the ingress of water into the excavation area, thereby maintaining the integrity and safety of the construction site

CONSTRUCTION

The construction of secant walls involves drilling overlapping concrete piles, which can be configured in various ways depending on the project's specific needs—such as hard-soft, hard-firm, or hard-hard combinations. This overlapping of piles creates a sealed wall that not only holds back soil but also significantly reduces water permeability. The choice of concrete mix and the incorporation of water-resistant materials within the piles further enhance the wall's ability to retain water, making it an effective solution in challenging geotechnical conditions.

What are the advantages of Secant Piled Walls?

Flexibility to maximise land use, fit complex site boundaries and weave between underground structures

Can be installed as a cantilever section or design to facilitate permanent anchors or temporary propping

The higher vertical tolerances can be achieved when using segmental casing during the installation of the secondary piles

Provides water tight retaining wall

DESIGN

When designing secant walls for residential projects, we use advanced tools like WALLAP and our proprietary in-house design sheets to ensure optimal performance and safety. WALLAP accurately models wall behavior under various load conditions, including soil pressure and groundwater levels, which is crucial in residential settings. Our in-house sheets further verify these results, allowing us to fine-tune the design for maximum stability and minimal deflection.