No!

Yes! Because they destroy infrastructure. Hence, they are devastating.

No - not directly!

Collapse of building structures in which they live, during the earthquake kills people. Hence, the real culprits are our construction practices and poor quality of construction. The conventional buildings instantly collapse without any warnings, during the unpredictable and sudden earthquakes

It is not feasible and economical to design and construct totally earthquake proof building structures, particularly to withstand very severe earthquakes of magnitude above 8.0 (Richter Scale) But it is very much possible to design and construct earthquake resistant building structures, though they may suffer huge damage under the influence of very severe earthquakes, they may not suddenly collapse and will not kill people.

In this concept the walls are not only designed to resist gravity / vertical loads (due to its self-weight and other living / moving loads), but they are also designed for lateral loads of earthquakes / cyclones. The walls are structurally integrated with roofs / floors (diaphragms) and other lateral walls running across at right angles, thereby giving the three dimensional stability for the building structures.

The simple example to prove it is a railway compartment or a bus coach, which will be subjected to lot of vibrations and base excitations (like artificial earthquakes) during their service period. They are built of so-called stiffened plate system. That means, it is made of a simple steel thin plate stiffened (strengthened / reinforced) by a grid of steel structural angles or channels like in shear wall system, made of concrete or masonry wall panels, which are reinforced, with a grid of steel rods. Hence, a shear wall system can effectively withstand earthquake forces.

The load bearing masonry is very brittle material. Due to different kinds of stresses such as shear, tension, torsion, etc., caused by the earthquakes, the conventional unreinforced brick masonry collapses instantly during the unpredictable and sudden earthquakes! The RCC framed structures are slender, when compared to shear wall concept of box like three-dimensional structures. Though it is possible to design the earthquake resistant RCC frame, it requires extraordinary skills at design, detailing and construction levels, which can not be anticipated in all construction projects!

On the other hand even moderately designed shear wall structures not only more stable, but also comparatively quite ductile. In safety terms it means that, during very severe earthquakes they will not suddenly collapse causing death of people. They give enough indicative warnings such as widening structural cracks, yielding rods, etc., offering most precious moments for people to run out off structures, before they totally collapse.

Yes, very much! After the post-earthquake surveys for over three decades, American earthquake experts have reported that, "not a single concrete building containing shear walls has collapsed and no lives were lost in the shear wall buildings, during a dozen moderate to severe earthquakes through out the world starting with the Skopje earthquake of 1963 through the Armenian earthquake of 1988".

Unlike RCC framed structures, which are to be built of columns, beams and slabs, the shear walls are to be ideally built of RCC walls and slabs. Though constructing RCC slabs are conventional, casting RCC walls are not! RCC walls are relatively quite costlier and it requires a special system of formwork, calling for more investment. In this context, Reinforced Hollow Concrete Block Masonry (RHCBM) construction technique is an optimal solution, both from the angles of cost effectiveness and structural safety.

RHCBM walls are constructed by reinforcing the hollow concrete block masonry, by taking advantage of hollow spaces and shapes of the hollow blocks. It requires continuous steel rods (reinforcement) both in the vertical and horizontal directions at structurally critical locations of the wall panels, packed with the fresh grout concrete in the hollow spaces of masonry blocks.

In many parts of USA and other seismically prone countries of the world, this construction technique is popularly being utilised.

The Structural Engineering Research Centre, Madras, (SERC) has recently completed a sponsored research project, "Development of disaster resistant building construction system with RHCBM and compared it with conventional construction systems". SERC proved that RHCBM is not only structurally efficient construction technique, but also cost effective construction system. In some of the construction projects of India, RHCBM technique is being utilised from the angle of ease of construction. But it requires good awareness to popularise that, RHCBM is an effective earthquake resistant construction system without involving additional costs and any special skills, materials, equipment, machinery, etc...