Why Concrete Cutting Solutions Are Key to Earthquake Responses

rescuers on earthquake rubble

Over the centuries, thousands of natural disasters have left their scars on communities. Of the types of disasters, the earthquake remains one of the most destructive, especially in urban areas. As a result, concrete cutting solutions are a core response feature.

There can be no doubt about the degree of destruction caused by an earthquake. This destruction is most evident in urban areas, where buildings, roadways and pavements can be both seriously damaged and completely destroyed.

In Nepal in 2015, over 9,000 people were killed in one of the strongest earthquakes in recent decades, measuring 7.8 magnitude. The capital Kathmandu saw historic pagodas, churches and temples collapse, as well as multi-level office buildings in downtown areas. Secondary effects, like delayed building collapses, were a constant concern.

The 2011 Christchurch earthquake in New Zealand claimed 185 lives, and its impact on structures in the city was severe. The six-storey Canterbury Television building and the four-storey Payne Gould Guinness House were amongst the most prominent buildings to be destroyed – both built using reinforced concrete.

Why are concrete cutting solutions so important?

The only safe way to deal with such urban destruction is to break down and remove the ruins and rubble. Initial efforts are done in the immediate aftermath of the earthquake to improve safety conditions while rescue operations are in full swing. But afterward, the work continues to clear areas to allow reconstruction to begin.

Often, buildings succumb to the impact of an earthquake in the weeks, months and even years, following the disaster requiring concrete cutting solutions as part of controlled demolition strategies. For example, in the period from the 2010 Canterbury earthquake to February 2015, some 1,240 buildings were demolished, including the Hotel Grand Chancellor and the 21-storey PricewaterhouseCoopers building.

But what can concrete cutting services actually do as part of an earthquake response strategy? There are three main tasks concrete cutters are ideally suited to:

1. Creating space to operate In

With the level of destruction that typically follows a strong earthquake, it can be very difficult for rescue teams to access the disaster area. Fallen buildings create mountains of rubble, impeding essential machinery like cranes and diggers from moving to the spots where they are needed. Concrete cutting solutions address such problems, cutting pathways through the debris, allowing passage through. There may also be issues with narrow locations, where the arm of a crane does not have sufficient room to rotate. Cutters can also be used to widen the space by removing segments of ruined walls or floors. Cranes can then fully rotate to lift and safely remove rubble and other debris.

2. Increasing Safety for Rescue Teams

By definition, rubble is never secure. But rescue teams often have to work on top of mounds of broken bricks, concrete slabs, pillars and girders. In some cases, the remaining structures in the devastated area can be dangerously close to total collapse, and semi-collapsed floors high above the rescue operation may teeter on the verge of complete collapse. That means they have to work in conditions that are unsafe. Concrete cutting solutions also address this threat, allowing rescue teams to cut away any hazardous elements on the scene, like the shattered end of a concrete floor. In this way, the area can be stabilised, making it easier for rescue crews to concentrate on the job at hand.

3. Gaining access to survivors

A third reason for having concrete cutters on hand is they can cut through debris to get to trapped survivors. Cutting through this concrete – in a careful and strategically secure way – creates a path for rescue crews to rescue these people and lift them to safety. Where victims are concerned, it allows them to be recovered and returned to their loved ones for burial.

Types of Concrete Cutters used

  • Hand Saws – The most practical concrete cutting saw, and therefore the most essential for concrete cutting solutions, is the hand saw. They can typically cut at depths of around 150 mm – so through floors and walls. Because it is hand-held and highly versatile, it can be used on almost any gradient and in the tightest of corners.
  • Road Saws – Road Saws is part and parcel of any concrete cutting kit dealing with paved walkways, pedestrian bridges and passageways. It is bulky, so is limited in regards to where it can be used. But its power when cutting through asphalt and concrete surfaces makes it ideal for removing damaged sections of roadway, and cutting through suspended concrete slabs.
  • Wire Saws –Concrete wire saws are powerful machines that can cut through massive concrete blocks, successfully separating large sectors of concrete and steel that may be hampering rescue operations. Using a highly effective diamond wire it can cut through thick broken slabs such as those found on modern bridges, or through thick concrete pillars. But it can be used on semi-collapsed buildings too. Perhaps its biggest advantage is that is can be used effectively in confined spaces.

Concrete Cutting Solutions from the experts

Clearly, concrete cutting is a vital service in any emergency response strategy after an earthquake. With the degree of structural damage to buildings, and the tight confines of many locations, concrete cutting saws have genuine uses at the scene. But it’s not something anyone can do.

Here at MegaSaw, we have been providing concrete cutting solutions to clients throughout Melbourne for almost 40 years. We know from our own experience that professional service providers are the only safe option when handling a location covered by rubble and damaged structures.

For more on our concrete cutting services, contact us either via email at info@megasaw.com.au or by calling one of our team at 1300-920-419.

5 Steps To Cutting Pavers Around Curves

cutting paver

There is nothing new to having paved driveways and parking areas in either residential or commercial areas. But the popularity of paver bricks, with their array of textures and colours, requires laying them with a certain amount of expertise. In particular, the range of layouts and designs requires cutting the pavers to fit around curves is a common requirement.

The technique applied when cutting pavers depends on the radius of the curve itself. The larger the radius will be, the slower the curve. Curves with greater than 1800mm radii, it is possible to cut clearly in one smooth arc. This is because the blade can be adjusted gently to match the curve line. This is ideal when laying pavers for a larger circular space, just like at the end of a driveway where cars may be parked.

But when the arc is fast (meaning the radius is small and the arc is severe), then several cuts will be needed. An example is a curved garden path through a lawn area or around flower beds. It could also be a laneway along the side of the home, linking the front and the rear of the property. Handling these faster curves is where the skill and experience of the saw operator comes into play, as they can be the trickiest to negotiate.

Types of Curves

When dealing with the tricky fast curves, there are 2 things to consider. These are the convex (external curve) and the concave (internal curve). With each, the pavers need to be laid first so that the curve can be mapped onto them.

When creating a large open space, the curve is going to be mostly convex, unless the design dictates otherwise. Where pathways are concerned, both types of curves apply as the opposite side of the paved pathway will be the opposite curve type. For instance, convex on the left side will juxtapose concave on the right.

Cutting Convex Curves

If the arc line projects outward, the task of cutting pavers convexly is easier than cutting concave curves. When laying the pavers down, mark the curve lines on them. But with a straight cutter blade, you may need to draw 3 or 4 straight lines to follow, using the curve as the guide. The angle change between lines should be less than 10 degrees to create a neat curved look.

Cutting Concave Curves

To cut a concave curve, a considerable amount of care should be taken. Again, the curve must be mapped onto the pavers and then a series of lines must be drawn also to complement it. Generally, just 2 lines are needed with one end of each line beginning on a free edge of the paver, intersecting inside it. What is important is that the arc or section of the arc is aligned accurately.

But while the geometry involved might seem a little confusing to those unaccustomed to working on such projects, the whole procedure can actually be broken down to just 5 simple steps. Here is a quick guide to cutting pavers to fit curves.

 

5 Steps in Cutting Pavers around Curve Edges

curved paver1. Map out the area

The area where the pavement should be placed needs to be clearly marked. Then, dig out and level the surface by spreading sand. If the area is to have some straight lines, use an edge restraint to clearly mark them. Doing this leaves spaces where the curved areas can be accommodated. On circular areas and winding pathways, the straight lines can be used to frame the curves.

2. Lay out the curves

This can be tricky but there are a few ways to make it a little simpler. Firstly, for large slow curves, use some garden hose instead of twine and pegs. This is because hoses curve smoothly. Then, sketch the curves on the ground using a piece of chalk. The garden hose technique suits the winding pathway too. However, the curves will be faster and the hose would need to have greater flexibility. Use pegs to fix the hose in place, then, mark the curves using the chalk.

3. Lay on the pavers

The next step is the easiest. Lay on the pavers as though filling a square or rectangle. The pavement can be practically completed without having to worry about cutting pavers to complement the curves. Just be sure that the pavers are properly laid, are flat and extend adequately over the curve lines. As you lay the furthest pavers, etch the curves over them. That way, you can easily follow the chalk markings beneath.

4. Spray pavers with lacquer

Spraying the pavers with lacquer can protect the guide line while cutting. Pavers can produce a lot of dust when they are being cut. These dusts fall back down onto the paver surface, hiding the lines. It is important to have a clear view of the guide line at all times. When you cut slow curves pavers, simply follow the line as drawn. But when the curve is fast, then it may be necessary to lift the pavers and cut before replacing them. Again, this depends on the desired design.

5. Install a flexible restraint

The final step would be to secure the shape of the paving. The narrow gaps between the pavers should be filled with sand and then compacted using a power tamper. But the tremors caused by tampering can easily shake the pavers out of place, unless they are properly secured. You need to fix flexible restraints using a mallet and metal pegs. To finish the job, cover the restraints with soil or grass sods whichever is appropriate for you.

Trust the Experts

Clearly, cutting pavers around curves is something that a novice is going to struggle to complete well. Hence, you need the help of the expert in paver cutting services. At MegaSaw, we have been providing excellent quality paver cutting services to clients throughout Melbourne for almost 40 years.

We apply a number of different techniques and use specialised saws as well as grinders equipped with diamond blades. We are fully prepared to deal with the specifics of the project and create cuts that are smooth and accurate.

For more information on our paver cutting services, contact us either via email at info@megasaw.com.au or by calling one of our skilled teams on 1300-920-419.