Seismic Disaster Mitigation in Pakistan Dr. Qaisar Ali Associate Professor and Deputy Director Earthquake Engineering Center Department of Civil Engineering NWFP University of Engineering and Technology, Peshawar Pakistan

Roadmap Basic terminology - hazard, risk, vulnerability and disaster Factors contributing to seismic disaster mitigation Hazard assessment in context of the Oct 08 earthquake Vulnerability of structures in context of the Oct 08 earthquake Recommendations for seismic disaster mitigation in Pakistan

Hazard, Risk, Vulnerability and Disaster ? How these terms are interconnected

Disaster An event causing widespread human or material losses which exceeds the ability of the affected community to cope using its own resources

Disaster risk = Hazard x Vulnerability Source: Satoru NISHIKAWA Cabinet Office JAPAN

Implications of Disasters A single disaster can wipe out annual GDP of a country. Losses from the current earthquake 80,000 dead 200,00 injured 4 million homeless Economic losses more than USD 5 billion Disaster Reduction is a MUST for Sustainable Development

Disaster mitigation Pre-earthquake scenario Post-earthquake scenario Realistic hazard assessment Reducing vulnerability through Seismic resistant design of structures. Implementation of code, inspection and monitoring mechanism. Post-earthquake scenario Emergency preparedness and planning

Seismic hazard zoning of Pakistan and the current earthquake Geophysical center Quetta, Met deptt. of Pakistan

Realistic seismic hazard assessment Realistic seismic hazard assessment is crucial because placing a low-seismicity region in a high hazard zone will require construction of costly structures thereby making them uneconomical. Similarly, placing a high-seismicity region in a low hazard zone will allow construction of relatively weaker structures thereby making them vulnerable to collapse during an earthquake.

Seismic Vulnerability Low Seismic capacity of buildings due to low quality of material, improper design and construction; buildings constructed on loose soil, or constructed in areas prone to liquefaction and land slides etc. will make the structures vulnerable to collapse during an earthquake.

Seismic vulnerability with respect to the Oct 08, earthquake

Stone masonry buildings constitute around 40% of the total building stock. (20% of it in cities and 80% in villages). Approx 95 % of buildings either completely collapsed or got severely damaged. Undressed stone masonry Dressed stone masonry Smooth round stones in mud mortar, or low quality cs mortars, no bond beams, no proper connections

30% of the total building stock (100% of it in cities, negligible in villages) was un-reinforced cement concrete block masonry having RC roof slab, out of which approx 50% either collapsed or got severely damaged. Low quality concrete blocks laid in mud mortar, or low quality cs mortars, no bond beams, no proper connections

Brick masonry building Muzafarabad Total stock of brick masonry building constitutes around 20%, (100 % in cities, negligible in villages), out of which less than 5% collapsed and around 15% got severely damaged. By and large the brick masonry has performed very well. Brick masonry building Muzafarabad

Less than 5% of the total building stock consisted of RC frame structures with brick or block masonry infill walls., 100% in cities. Generally performed well, The collapse and damage were found to be the result of improper design, detailing and low quality material. Improper lap length

Strong-beam weak-column

Incredible

Improper lateral reinforcement

Water tanks collapse occurred as far as 200 km from the epicenter

Original position of deck 1 meter displacement Life lines---Bridges

Pipe lines transmission lines

Massive land sliding washed out entire villages

Approx 17,000 school children killed Letter written by Sony, a student in Nepal Ref: Program on Educational Building, OECD

Issues contributing towards seismic vulnerability None-existence of seismic design guidelines and building codes. site specific ground characteristics for seismic design. scientifically determined indigenous material properties. trained professionals for carrying out construction activities in seismic prone areas awareness of general public for realizing the seismic risk. Implementing/regulating and inspection mechanism for construction monitoring

Emergency preparedness and planning In the post-earthquake scenario the quantum of disaster can increase enormously due to lack of effective emergency preparedness and planning strategies.

Measures to be taken to avoid disasters in future ?

Short Term measures For the reconstruction of the affected areas, general seismic guidelines and building recommendations can be adapted from already established international codes. This should act like an interim code and not as a permanent code for the country. To develop a proper seismic code for the country will take time. The enactment of a law for strict enforcement of these recommendations is also required. Training should be imparted to the contractors, masons, construction supervisors and local government hierarchy at the union council and tehsil level for effective reconstruction and rehabilitation activities. The design and construction of educational institutions, hospitals and other important government buildings should be given special attention. The EEC should be involved in this process.

Short Term measures--- Construction of new buildings in the areas prone to landsliding and liquefaction should be avoided. Rapid assessment of damaged public and private buildings is crucial. There should be authorized qualified technical professionals to carry out these activities. (Fear among the people is so high that even some slightly damaged buildings have been declared as uninhabitable.) Repair, strengthening and /or retrofitting of existing buildings deficient in seismic capacity is also vital.

Improving the seismic performance of masonry structure-general guidelines (ref Eurocode-8) Note: such arrangement provide overall integrity and stability to the structure.

Long term measures Installation of strong motion net work Development of seismic hazard maps based on PGA and PGV, liquefaction and landslide maps, micro zoning for highly seismic prone regions etc. Development of seismic code for the country Seismic risk assessment for various categories of buildings and engineering structures. Structural assessment of important buildings such as dams, long span bridges, educational institutions, hospitals, secretariat etc and their strengthening, if required.

Long term measures (contd) Technology development for low cost base isolation and damper systems for brittle structures. Development of repair and strengthening techniques for seismically distressed local structural systems. Development of disaster mitigation methodologies. Seismic risk assessment for sustainability of life lines including, highways, railways, Gas, Sewerage and Water pipe lines and electricity transmission lines etc.

Proverb by Japanese Physics Scientist Dr. Torahiko “Natural disasters will hit us by the time people have forgotten about it”

Thanks