Have you ever wondered how building structures stand without collapsing during construction and how workers move in and around tight spaces safely? The answer is: it’s possible because of the process of shoring.
Let’s take a look at the details of shoring and its types.
What is Shoring?
Shoring refers to the process of providing temporary support systems to building components during construction, excavation, demolition, foundation, and renovation work. It is done with the help of support props such as timber, aluminium, or steel rods. The main objective of shoring is to prevent collapses by offering support, avoid damages, and ensure the safety of workers. Shoring can provide support or balance in various directions, like horizontally, vertically, and diagonally.
Importance of Shoring in Construction
- It plays a major role in providing a balanced structural system temporarily to prevent collapse of building elements during construction. They act as an additional support system for roofs, walls and other structures.
- Ensures safety for workers when they work in small construction spaces.
- This process is also carried out for repairing cracked walls and making sure of avoiding further cracking by stabilising and reinforcing building structures.
- It helps in distributing loads evenly during construction, therefore improving the strength, durability, and stability of building structures.
- During construction, walls have the highest chances to bulge out due to water absorption, moisture, or mistakes made in building techniques. Shoring helps in resisting bowing or buckling and further damages.
Differences Between Shoring and Scaffolding
Scaffolding refers to the process of building a temporary structure to provide support for workers on the construction site. It provides safe access and movement in and around the construction site. However, shoring refers to the temporary structure made to prevent collapse of building elements by giving stability. Scaffolding is a separate and freestanding structure, whereas shoring is often connected with the existing building structure.
Materials Used for Shoring
Different materials can be used for shoring, each with its advantages and disadvantages. Some of them are:
Steel Beam Shoring
In this system, steel beams are used to provide support during foundation work, excavation work, and other structural activities. The major components used are:
- Steel H-Beams: Offer horizontal support
- Steel Posts: Connect H-Beams to the ground, providing vertical support
- Base Plates: Transfer loads from posts to the ground
- U-Channel Brackets: Secure H-Beams to posts
- Steel Wire Rope: Used for extra lateral support and stability
Steel beam shoring is commonly used in bridge construction, auditorium construction, trench work and foundation renovation works. It has some advantages and disadvantages, such as:
Advantages | Disadvantages |
Can withstand heavy loads and has maximum strength with minimal mass. | High setup costs |
It can be customised easily and has flexible installation. | Produces excess noise and vibration during installation. |
High durability and can be used in various soil conditions. | Requires specialised equipment and skilled labour. |
Resistant to weather conditions. |
Heavy Timber Shoring
Timber beams or planks are used to offer strength and carry heavy loads of structural elements. The common components include:
- Solid Sawn Timber Beams: Act as lateral support system
- Timber Posts: Connect the beams to the ground vertically
- Timber Planks: Used as soil retention panels
- Wooden wedges: Ensure a tight and stable structure by maintaining alignment and position.
Heavy timber shoring is used in small excavation areas, tunnel work and other construction activities. It has its own sets of benefits and disadvantages as well.
Advantages | Disadvantages |
It is less expensive compared to other shoring methods | It cannot withstand heavy loads |
Environmentally friendly as it is easily available and can be recycled and reused | It is prone to moisture absorption, degradation and pest attack |
It is easy to set up and install | Timber shoring has a shorter life span and is less durable compared to other shoring materials |
Sheet Pile Shoring
It is a construction technique that uses profiled sheet piles, installed by drilling and driving them into the soil, to act as a barrier and supporting system, preventing collapse during trench work and excavation. Types of sheet piles used are:
- Steel sheet piles
- Vinyl sheet piles
- Concrete sheet piles
- Timber sheet piles
Sheet pile shoring is suitable for deeper excavations, tunnel projects, and coastal projects because it can effectively manage groundwater systems and support other underground works. Let’s look at the pros and cons of sheet pile shoring.
Pros | Cons |
Has high load carrying capacity | Highly expensive to purchase and install |
It can manage groundwater levels by preventing infiltration and controlling seepage | Installation generates high levels of noise and vibration |
Effective in diverse soil conditions, including clay, sand, silt and rock. | Needs careful handling because sheet piles are prone to damage |
Fast installation and speeds up project completion | Sheet piles become less resistant to corrosion and abrasion if not maintained properly |
Types of Shoring
1.Raking Shores: The application of raking shores is to give temporary lateral support to the walls, making them withstand forces and preventing collapses. Rakers are support elements that are inclined at an angle of 45-75 degrees and often consist of small braces that provide additional support. They are generally fixed to the wall (or other vertical structures that require temporary support) with the help of cleats, wall plates and needles.
2.Flying shores: Flying shores offer horizontal support to parallel walls of adjacent buildings to avoid collapse during the construction or demolition of central buildings. This temporary support is offered during roof or wall construction or renovation of tightly spaced buildings. They play a vital role in resisting tilting or overturning of nearby buildings.
As the name suggests, flying shores are made to provide lateral support without touching the ground. They transfer load through anchored structures that extend between two building frames. During excavation, flying shores are used between the walls of trenches to prevent soil collapse. They are usually horizontal beams bridged over the trench and supported with struts at each end to provide safety and stability.
3.Dead Shores: These are used to provide vertical and horizontal support to structural elements when there is no support below it. For example, in roofs without walls below or walls with openings below it.. Dead shores carry the dead loads, which means the permanent loads of walls or roofs, vertically. It is called dead shoring because once the process is completed, it is non-adjustable and left in place for a long period to maintain stability.
4.Hydraulic shores: This system is commonly used for heavy construction work, deep excavation, and bridge repair work. They are generally made up of steel beams, which have a high load-carrying capacity, are easily adjustable, and are most effective in installation. They give support through hydraulic pistons at both sides of trench walls to block the collapsing or falling of gravel or sand in the construction work.
Safety Considerations
- Proper planning: Evaluate the designs and review the plans before installing the shoring system. Weight of the building structures, internal pressures, soil conditions, and other factors should be considered before starting the process.
- Regular inspection and proper maintenance: Check and verify the stability of shores. Monitor for any deterioration, damages, or corrosion in the shoring system and arrange for replacements and repairs if needed.
- Proper installation and alignment: Shores are installed to offer support and prevent collapses, but if they are not aligned or installed properly, it can lead to a mishap in construction work. Make sure they are aligned correctly.
- Educate the workers: Engineers should prioritise the safety of workers by creating awareness. They should teach them about the handling of heavy materials and tell them about the hazards of the shoring system, particularly in trench areas.
Conclusion
From the above discussion, it is clearly evident that shoring helps immensely in construction by offering temporal support and preventing collapses. It plays a critical role during alteration or renovation work. The success of shoring relies on the effective planning, installation, and maintenance of support structures.
FAQs
They prevent damages or collapses, enhance the safety of workers, and help in maintaining the strength and stability of structures.
They are left in place until the building elements gain sufficient strength and can stay erect without collapsing. The exact duration depends on the material used for the element. For example, concrete elements will require a minimum of 7 days before the shoring can be removed.