13 Apr, 2015
Sarah Rooney and Nayan Pokhrel (Fixer)
Laxman looks at a building in Kathmandu, Nepal, he isn’t concerned with the aesthetic proportions or the comfort it provides to its inhabitants; he is looking for weakness. He examines the walls to assess the quality of concrete or brickwork. He measures up load-bearing beams and columns to gauge their strength. He searches for cracks, patches of damp, or signs of subsidence. Ultimately, he is looking to see if the building will withstand a major earthquake.
Laxman works as an engineer at John Sanday & Associates architectural firm in Kathmandu and has, with additional training in Macedonia and a decade of specialized experience, become an expert in the fastidious science of earthquake-resistant construction methods. Thanks to government efforts and civil society campaigns, earthquake awareness in Nepal has been steadily increasing over the past decade and much of Laxman’s work now involves trying to bolster existing structures or ensure that new ones are built to the safest possible standards.
The deadly perils of liquefaction and poor planning
Nepal sits atop the two major tectonic plates that gave rise to the world’s highest mountains, the Himalayan range. More seismic activity is recorded here than almost anywhere else in the world. Within Nepal, the Kathmandu Valley is considered the most at-risk zone; once a prehistoric lake,the valley’s soil is rich, fertile and perilously soft. “Liquefaction is what we fear the most,” says Laxman. “When we assess a building we must first determine what kind of soil it stands on. If the soil is very soft – containing a higher percentage of silt and water – it is in danger of liquefying during heightened seismic activity which means the building on top of it will be in very great danger of sinking, toppling or collapsing completely.”
Nepal’s last major earthquake took place in January 1934, killing thousands of people and destroying at least a quarter of all buildings in the valley. Today, the effect of a major quake could be exponentially worse. In recent decades, the valley’s population has expanded at a rapid-fire rate and the urban sprawl – emanating from the three closely connected cities of Kathmandu, Patan and Bhaktaphur – now covers most of the valley floor and is home to an estimated 2.5 million people.
“There has been no adequate urban planning,” says Laxman, who was born in Kathmandu in 1963 and witnessed firsthand the city’s dramatic growth. This lack of planning will exacerbate the effects of a major earthquake – the proliferation of high-rise buildings in residential zones creates high population density in vulnerable areas, the narrow streets are inaccessible to emergency vehicles, and the lack of open spaces means people have nowhere to run to for safety.
“I worry about the bridges, too,” says Laxman. “Due to unregulated removal of sand from the river the foundation pads are nearly exposed. If they go down there will be no access roads and Kathmandu could be totallycut off, resulting in shortages in food and other necessities. Electricity lines will also go down, water pipes will break, and the communication system will be non-functioning. The fire brigade and ambulances will be unable to reach the people who need it most.”
Strengthening Kathmandu, one building at a time
With such dire predictions, the only sensible response is to try and ensure that the valley’s sizeable structures are as robust as can be. The process is conducted in three stages. The first step involves a Rapid Visual Assessment. “Here we are looking at very basic things,” explains Laxman. “Is it a framed structure or a cantilevered structure? Are the beams and columns aligned? We check the structural layout, code compliance, and quality of workmanship. Our job at this stage is to identify weaknesses that are visible to the eye.”
The results of this assessment are compiled in a Vulnerability Sheet and, if further work is required, the firm recommends a Detailed Structural Assessment. This second stage involves an in-depth examination that includes conducting soil tests, scanning beams to calculate stress levels, and checking concrete density and strength, etc. With this information inputted to his computer, Laxman can create a 3-dimensional analysis model and replicate the impact of an earthquake to gauge the building’s resistance to heightened seismic acidity, i.e., if/how it will collapse.
The third and final step is to retrofit the building and strengthen its vulnerabilities. Laxman’s firm is currently in the process of retrofitting ten hospitals that represent the most vulnerable among 60 hospitals they inspected. From private homes to large offices, each project requires Laxman to draw on an extensive database of knowledge ranging from the geological properties of different soils to a historical and architectural understanding of the brickwork used in Kathmandu’s countless ancient monuments. Laxman says it is this variety that inspires him: “I really enjoy this work because each and every building we assess presents different challenges. At each place we encounter a new set of problems and our job is to come up with a new set of solutions.”
Good engineering saves lives
Most informal or small-scale construction sites in Nepal pay little heed to the government’s building codes but Laxman believes the time has come for clients, contractors and builders to insist on more rigorous standards – for their own safety. “Because of this earthquake situation, any new building constructed in Nepal should follow strict building codes,” emphasizes Laxman. “It must be good design, good material, and good workmanship. Earthquakes don’t kill people; poorly constructed buildings do.”
Working against the clock to prepare for an earthquake now estimated to be overdue doesn’t depress Laxman. Rather, he keeps his focus firmly on his job. His computer’s hard-drive and the bookshelves of his office are stocked with an ever-growing number of reports, each one documenting a completed assessment or retrofitting job. In addition to structural recommendations, the reports also advise clients on the best escape routes as well as the safest and most dangerous areas in the building assessed. “Generally speaking,” advises Laxman, “It would be best to be in an open space but if that’s not possible, stay away from outer walls and large windows, get down to the ground floor, take shelter beneath a sturdy desk or door frame and assume the ‘triangle of life’ [duck, cover, and hold].”
This article is part of our ongoing series Tales from the Himalaya: Urban Lives in Kathmandu.
Photos by Nic Dunlop for Asia Dialogue