Fast Track Projects through Safer Working Environment at Construction Sites

The concern for construction projects getting delayed is increasing in developing countries. There are multiple factors which can lead to delay in big construction projects. Some of these impact the schedule directly while some have detrimental effect on schedule and time in indirect ways. One of the major factor amongst such indirect ones is the prevalent safety conditions at the work site. Safety hazards at the site highly negate the workers’ interest thus leading to poor quality being built in. It leads to overall project delay as well since a lot of time is wasted in safeguarding the work environment on a daily basis.

Developers / Owners are clear that safe working environment for workers will result in better quality of workmanship since it takes away the suspicions around security from the mind of a worker. This helps workers better focus on task at hand and has major positive impact on projects. It increases the efficiency in workers’ performance and leads to better quality, lesser rework and improved timelines.

The fatal injury rate for the construction industry is higher than the national average in this category for all industries. Potential hazards for workers in construction include:

• Falls (from heights)
• Trench collapse
• Scaffold collapse
• Electric shock and arc flash/arc blast;
• Failure to use proper personal protective equipment; and
• Repetitive motion injuries

Source: https://www.osha.gov/Publications/OSHA3252/3252.html

One effective and definite way to increase the safety in construction projects is to minimize the work at height (per statistics, working at height accounts for most number of injuries). But, this is easier said than done. Over centuries, we have been used to constructing structures from bottom to top which has always led to height related hazards to workers during construction of higher floors. There have been marginal improvements to lessen the hazards, some of them being - usage of proper personal protection gadgets, pre casting, off-site construction, etc. Though these were helpful in reducing the overall risk, but, all of these approaches were small continuous improvements on the path of providing incident free environment at construction sites. To eliminate the risk to a substantial degree, it required a ‘disruptive’ change, a change which could be brought about only by questioning the basic assumptions of construction practices. It required analyzing the trends from past projects, going to the whiteboard and drawing and connecting all dots to come up with a fresh solution.

A couple of such disruptive thinking approaches have been game changers in this space.

1. Top to down approach: Successfully executed for multistory buildings in residential and commercial towers. In this approach, the top floor is casted first and lifted to the desired height.

Hydraulic jacks are used to lift the full floor plate along with the dry wall and other finishing material such as external cladding, flooring etc.

Subsequently, one by one, other floors are casted and lifted.

2. Lifting the Roof with Strand Jack: Effective method for industrial buildings, wherein several services are supported through roof, which is usually 6 to 9 m high.

In the conventional method of construction, the roof is erected first and all the services are installed using scissor lifts / scaffoldings. This installation process reduces the efficiency and increases the installation time. The safety risks are also very high, due to taller structure.

The effective approach is to change the sequence of activities by installing all the services (HVAC ducting, electrical cable trays & lights, fire protection system) at a working level height, i.e., 1.8m to 2.4m above the finished floor level. After the installation of all services, the roof would be lifted with the strand hydraulic jacks and the columns are connected to the roof structure by bolted connection or fast setting concrete placed over the columns.

The strand jacks are placed over the columns and they pull the roof from top. Strand jack has an inbuilt pull and hydraulic wedge locking system which is automated by a software program. This concept is widely used for Airport hanger, Industrial projects.

These approaches increase the safety thus leading to increase in workers’ efficiency which ultimately leads to substantial reduction in the schedule. These approaches also meet the larger objective of ensuring that due respect is given to the health and life of workers. Providing a hazard free and safe working environment is of paramount importance and should be given due diligence.