28 April - 4 May 2017 #856

Buildings not strong enough

Mahesh Acharya in BBC Nepali, 24 April

Bikram Rai

Two years ago, when the earthquake destroyed the mud-mortar houses in Kathmandu Valley, it convinced many that cement buildings were safer. But a new study has revealed that many of the reinforced concrete construction (RCC) buildings in the Kathmandu Valley do not meet minimum government standards and would not withstand a strong earthquake in future.

The two year-long study titled ‘Project for Assessment of Earthquake Disaster Risk for the Kathmandu Valley,’ led by the Ministry of Urban Development in coordination with Japan International Cooperation Agency (JICA) and other government agencies, found that out of 250,000 RCC houses in Kathmandu only 27,000 or so followed proper engineering and design guidelines.

“Only six per cent of the RCC houses in Kathmandu Valley follow engineer-approved designs, whereas 48 per cent of houses are non-engineer RCC building, meaning they were constructed by the house owners without keeping the earthquake safety in mind,” explained Suman Salike, senior divisional engineer at the Ministry of Urban Development who was involved in the assessment.

According to the 1993 building code, an RCC building needs to have 12×12 inch pillars, but engineers involved in the assessment said that many of the RCC houses were found to have 9×9 or 9×12 inch columns.

“There are criteria for load calculation in the building code, and the building code at the time deemed that a 12×12 inch column would sustain the load of a building with a certain number of floors,” said Ram Bahadur Thapa, head of the construction permit division at Kathmandu Metropolitan City.

This rule is applicable to buildings of up to three storeys having a footprint of less than 1,000 sq ft. Today, most concrete buildings in Kathmandu are more than three floors and need pillars and beams that are stronger, with bigger dimensions and more rods.

Experts also said that the building codes need to be followed more strictly and amended accordingly to build safer and stronger houses. “If you don’t upgrade this building code, you will have to suffer damage equal to or more than in 2015. That is why it needs to be amended,” said Riyochi Takahashi of JICA, who was involved in the assessment.

Along with the study, the government has also started discussions with national and international experts to amend the criteria in the building code so it reflects the requirements of taller buildings and stronger earthquakes. There are around 450,000 houses in the Kathmandu Valley, about half of them are of RCC and most do not meet the specifications in the building code.