A time to rebuildEvidence from the past quakes clearly indicates that one of the major causes of building damage is foundational failure
The devastating Gorkha earthquake killed over 9,000 people and caused massive destruction to physical infrastructures. Yet, even after nine months since the quake, the majority of the victims are still residing in temporary shelters and facing a harsh winter. In order to bring the condition back to normal, rapid reconstruction of earthquake-resistant buildings is needed and it should be initiated as early as possible.
The government has finally put the National Reconstruction Authority in place but the reconstruction works are yet to begin. The process for the formation of the Reconstruction Authority had been halted for several months due to political stalemate, but in December 2015, the Chief Executive Officer for the Authority was finally appointed. Still major tasks, such as hiring competent manpower and selecting the right technology for the reconstruction, are to be completed, which is required to initiate the reconstruction works. In addition, appropriate plan and policy, revision of the existing building codes and guidelines are required to ensure that the new infrastructures are earthquake resistant.
Things to consider
While revising the national building codes and guidelines, the government should consider the lessons learned from the past quakes. The findings and recommendations of the national and international researchers, who have actively participated in the study of post earthquake damages, can be used as reference. Besides revision of codes, it is also necessary to rectify the flaws in building designs.
For instance, current engineering construction practices are mostly focused on the structural design, while geotechnical aspects are least emphasised. However, evidence from the past quakes clearly indicates that one of the major causes of building damage is foundational failure. Structurally intact buildings have been damaged due to excessive settlement and tilting. Moreover, the shaking intensity was found to vary depending upon the soil type and topography during the recent earthquakes. Thus, geotechnical aspects should be given due attention in the reconstruction process.
Moreover, merely developing building codes does not help build a quake-resistant nation unless they are strictly implemented. Appropriate manpower in corresponding bodies such as the Village Development Committee or the municipality should also be appointed to ensure the enforcement of the building codes. Furthermore, the role of public support is very important, as without the support it is impossible to implement the codes effectively. Lack of quake-resistant buildings in rural areas resulted in more casualties and damages during the recent quakes. So to garner public support, urban-centered awareness programmes should be shifted to rural areas, where most of the illiterate and vulnerable people reside.
Need for research
Besides building codes, other design references such as seismic hazard maps and liquefaction hazard maps should also be developed and revised frequently, based on the understanding of local geographical and geological condition of the country. But this is only possible if we have sufficient research in these fields. In most of the developed countries, academic institutions and government organisations are actively involved in such research and a large portion of the government budget is allocated to support these organisations. Likewise, even in Nepal, the government should allocate sufficient funds to research. But such research work can only be accelerated after establishing a well equipped laboratory such as a geotechnical earthquake engineering laboratory, which is necessary to understand the response of the ground and structures during the quakes, and the cause and mitigation methods of the seismic hazard.
But in the present context, the foremost task of the government is to start the reconstruction works. And certainly, the massive reconstruction works will also increase the economic activities of the country, which are also direly needed at the moment. For long-term stability, the key concern of the authorities should be the use of right technology and construction materials during the reconstruction process to ensure quake-resistant construction. This is only possible by mobilising competent civil, structural earthquake engineers and geologists in the reconstruction process.
Lama works as a geotechnical engineer at Tetra Tech, US