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Sunday, 25 October 2015





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Decelerating to detour

The Kokmaduwa landslide, which forced the closure of the Kokmaduwa-Imaduwa stretch of E01 has red-flagged many construction and safety concerns :

The landslide at Kokmaduwa, which led to the Kokmaduwa – Imaduwa stretch of the Southern Expressway (E01) being shut down for almost a week, has red-flagged several pertinent questions about the 126.1 kilometre stretch of superhighway, primarily about preventive measures, safety of motorists, and the quality of construction ensuring these measures are fool proof.


Southern Expressway consists of 126.1 kilometres spanning from Kottawa to Matara. The maximum operating speed for this section is 100 kmph. The original plan was to extend the Expressway to Hambantota with the intention of linking the Mattala Airport and Hambantota Harbour to the Commercial Capital, Colombo.

One would expect a super-highway, which sets a 100-km speed limit and invites motorists to step on the gas, letting loose the hunger for speed, to be proven and re-proven safe, no matter what the contingency. Yet, since its inauspicious opening when wildlife from the area turned out to menace the motorist, to certain stretches getting flooded every time it rained, the expressway has turned ‘absolute’ into ‘questionable’. And the landslide debacle only serves to cement that concern.

Experts in the field not only question the infrastructure provided for the ‘Safety of the Motorists’ using the Expressway, but also the quality of the construction.

Clearly visible

The ravages of the Kokmaduwa landslide is clearly visible to anyone, driver or passenger, on the Expressway. The irony here is that the landslide exposed, not just the ravaged landscape, but also the ‘so called’ preventive measures undertaken earlier by the foreign contractor or his local sub-contractor.

Inquiries made from the villagers living in the vicinity reveal that around four to five years back, there was a landslide almost at the exact same spot. The sliding earth piled up on the hard shoulder of the Expressway, putting a dampener on the handing over of the Expressway to the authorities.

Billons of rupees have been invested on the construction of the Expressway where SAFETY of the travelling public – who pay a Toll Fee - is a vital aspect; and the inconvenience to expressway users, caused by obstructions cannot be measured in rupees and cents.

‘Not a natural disaster’

There are accepted practices the world over in applying mitigatory measures in the case of cuttings in the construction of Highways and Railways- i.e. to prevent earthslides originating within the cutting, obstructing the free movement of traffic. Various engineering methods and proceedures are adopted by the Civil Engineers and Engineering Consultants in charge of these projects and the client, the consultant and the contractor are all responsible for failures.

In the context of the Kokmaduwa disaster, the question arises as to who should be blamed and who should accept responsibility. Experts point out that landslides such as what occurred in Kokmaduwa cannot be considered a ‘Natural Disaster’ when massive amounts have been spent on preventing such a disaster.

They point out that Sri Lankan Geological experts are quite conversant and capable of handling such projects without subsequently ending up in calamitous situations.

A Senior University Don expressing his views in the procedural forms available for prevention of slides on cuttings, explained the general procedure would be to do design drawings having checked up all relevant data with regard to soil conditions, depth of soil cushion, moisture content, rate of absorption of water, permeability, seepage, and rock formations among other things.

Having studied the photographs he is of the opinion that the construction work has been carried out haphazardly as indicated in the photographs in Soil Nailing, linking up the nails at berm level, absence of paved berms with drains, rock bolting, shotcreting the surface according to the stipulated thickness and the absence of wire-netting, draining off of ground water through horizontal drains, absence of proper surface water drains,(damaged pieces of drains mirrors the standard of work of the contractor), have not been undertaken as per correct design drawings and the construction technology adopted is visibly very inferior.

Not an aberration

In the context of the above, the experts say there is an immediate need for an inquiry to be conducted by a panel of experts from the Universities of Peradeniya and Moratuwa and the National Building Research Organization (NBRO) in fixing up of responsibility for the damage and the subsequent cost involved in the remedial measures and to recover the money spent, from those responsible.

This Panel, they say should study from the very first instance of the landslide a few years back, the design drawing that are available with NBRO; and determine whether these are acceptable as suitable: and whether the contractor selected was suitably qualified and experienced in such works; whether the contractor has conducted the work to acceptable standards, whether he had engaged sub-contractors in the work; whether sufficient supervision had been afforded; and whether the work had been accepted and certified fit for payments – all of which involved millions of Sri Lankan Rupees – as part of foreign loans. The Kokmaduwa earth slip might have taken many by surprise, but there is no guarantee it is going to be a one-off aberration, given the fact that there exist many more earth slip prone areas, similar to Kokmaduwa along the Southern Expressway.

Text and pix by Special Correspondent

Looking for a permanent solution

The Kokmaduwa – Imaduwa stretch of the Southern Expressway that was closed for almost a week ago due to a landslide threat, has been opened for traffic as usual, confirms the Ministry of Highways. According to its Secretary D.C. Dissanayake, the Expressway will be opened for public as usual, but the Police, officials of the Road Development Authority (RDA) and the National Building Research Organisation (NBRO) will be on alert 24x7 working on the spot. “Within few hours after the emergency close down, the officials were able to reopen the expressway,” Dissanayake said.

Assuring that as soon as the rain ceases, officials of the RDA and the NBRO would start working on a permanent solution, Dissanayake pointed out that all measures have been taken to stabilise the area along the cut slope.

The NBRO has fixed an early warning system to detect any movement along the cuttings, which is linked to an alarm system and to the traffic lights. “At any emergency situation, the alarm system will get activated and vehicles can be stopped until the situation is stable,” he said.

Meanwhile officials of the RDA’s Expressway Operation, Maintenance and Management Division, claimed there was no significant drop in the number of vehicles using Kokmaduwa- Imaduwa stretch of the Expressway. “When the Expressway stretch is closed, vehicles exit from the Kokmaduwa intersection and entre from Imaduwa. Therefore vehicles can move almost in the normal way,” Acting Director, R.A.D. Kahatapitiya, said

According to Kahatapitiya, the cut slope is caused by the water flow of a manmade rainwater draining system of a government estate, located at a higher elevation, a few kilometres ahead of the affected spot. As Kahatapitiya explained the water pressure building up underneath the soil had affected the earth layers of the cut slope to move.

He said the early warning system got activated on October 2 and they were able to immediately inform the police to stop and divert traffic.

The NBRO has established an operating room functioning around the clock, located on the other side of the Expressway, facing the site of the earth slip . An extensometer, which is the main gadget of the early warning system, has been fixed to the cut slope to detect movements.

The NBRO has also taken measures to lower the water pressure in the soil. “The surface water draining systems needed to be cleaned and cleared for the rain water to properly drain,” said K.N. Bandara, head of the Geotechnical Engineering and Testing Division of the NBRO, adding that pipes have been drilled into earth to remove the accumulating rain water under the ground.

“Water flowing from high elevations seems to get accumulated under the soil surface and we have taken necessary measures to drain this water out. Therefore at the moment we have managed to lower the water pressure on the loosened earth chunk,” explained Bandara, further elaborating that ‘soil nailing’ could be a possible solution to stabilise the cut slope. However, he said there was a need to carry out a geotechnical and geophysical investigations before coming to any conclusion. He also said the NBRO is planning to start scientific investigations within the next few days, to draft a detailed engineering design for a long term solution.


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