An important element of diaphragm wall construction that anchors modern infrastructure stably are quite literally ‘anchors’ or retractable anchors to be more specific.
The anchor system, once established on the site, provides lateral stability to the diaphragm retaining walls during the excavation process and concrete pouring. Moreover, they offer a massive advantage for excavation areas with remarkably low horizontal deflections.
Presently, there are two types of anchor systems widely used for diaphragm retaining wall construction, and modern engineering institutes, like Heritage Infraspace (HIPL), prefer using retractable anchors.
Why is it so? How are retractable anchors different from traditional ones? And what are the advantages derived from them? We will answer all the queries in this guide.
What exactly are Retractable Anchors?
Retractable Anchors used by HIPL for diaphragm retaining wall construction
Once the retaining wall is complete the anchors can be effectively removed by retracting the steel bar from the grouted hole. Hence giving it the name, ‘retractable anchors’.
A retractable anchor is a ground anchor that can be easily removed or repositioned without damaging the surrounding soil or structures once the construction process is complete.
The idea behind having an anchored wall system for diaphragm wall construction is to create an internally sturdy system that will counter and kind external failure. And just like a traditional anchor, this is achieved by placing a steel tendon or bar inside a pre-drilled hole in the ground.
The pit is then filled with grout that slowly sets around the bar or the cable, locking it in place. The other end of the anchor is attached to the diaphragm wall reinforcement cage such that this formation provides lateral support during the excavation and concrete pouring.
Advantages of using Retractable Anchors
So what makes retractable anchors so preferable among diaphragm retaining wall construction companies all around the globe? Mentioned below are a few of them:
Well, for starters, retractable anchors require fewer resources when compared with traditional ones. For instance, with a 4T traditional anchor, you will utilise 4 different cables or bars. But with a retractable one, you only require 2.
Easy to reposition:
Secondly, they are flexible, which means they can be repositioned whenever the need arises to provide additional support or to dodge any pre-existing obstacles in the construction area.
Suitable for all soil types:
Another massive advantage of retractable anchors is that they can be used in a variety of soil conditions. Whether the soil is rocky, sandy, or clay, retractable anchors can be used to provide lateral support to the retaining wall.
Retractable from neighbouring property:
A noteworthy benefit of using retractable anchors comes forth if there is an adjacent structure next to the construction site. Since it does not forever stay in the soil, one can avoid any dispute over intrusion in the neighbouring property and damaging it.
Can be reused:
The biggest advantage of retractable anchors is that they can be reused in other projects as well. Once the diaphragm retaining wall construction is completed the anchors are easily removed and hence reused.
While discussing details about retractable anchors, it is essential to note that their implementation and retraction require years of expertise, specific types of equipment and professional knowledge.
Retractable anchors cost slightly higher than traditional anchors. However, their flexibility, durability, and reusability benefits make them a noteworthy investment for deep basement construction projects.
Anchored wall at HIPL construction site
Expert tip: Hiring a construction company that conducts property tests (eg: Ultrasonic, RIR, tensile strength etc) ensures quality and the best results.
Few factors to consider when using Retractable Anchors
The must-consider factors while utilising retractable anchors include:
- Soil condition
- Load requirements
- Anchor age and condition
- Team expertise
Note that for proper maintenance and management of diaphragm retaining walls it is vital to know the anchor age and ensure that it is rust-free. Because when stressing or retreating, the anchor coil must not break or it may yield unexpected threats to the workers on site. That is why opting for seasoned engineers and trained workers is a must while anchoring.
Expert tip: Never keep retractable anchors directly on the floor or in moist places.
In conclusion, retractable anchors are an essential component of diaphragm wall construction in India and across the globe. They provide crucial lateral support during excavation and concrete pouring and can be easily removed or repositioned after the construction process is complete.
Their flexibility, durability and versatility mean they can be used in a variety of soil conditions and construction projects, making retractable anchors reliable and effective.
If you are looking for smart geo-technological solutions, such as anchoring and diaphragm wall construction for dams, metro, and deep basements, drop us an email at firstname.lastname@example.org.