Civil Engineering Report: Earthquake-Resistant Structures in Nepal

This technical report focuses on optimizing elements for earthquake-resistant construction, particularly in the context of Nepal. The report examines various methods to improve building resilience, including the use of seismic belts in gable walls, vertical reinforcement in masonry walls, and the implementation of RC shear connectors in rubble walls. It also explores the use of bamboo reinforcement, timber beam rings, and external cane and rope mesh for wall stiffening. Furthermore, the report discusses diaphragm stiffening techniques, such as steel strap installation, RC topping casting, and timber plank installation. Recommendations include constructing taller, more flexible structures, utilizing specific construction materials like wood and steel, and incorporating strategic beam placement for energy transfer during earthquakes. The report also suggests special foundation designs and the use of flexible cushions to mitigate earthquake damage. The document references several key sources and provides a comprehensive overview of earthquake-resistant construction strategies.

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STATEMENT OF INTEREST
Student’s Name
Institution
City
Date

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Statement of Interest
It is my interest to make a contribution to and participate in the project that focuses on
optimization of specific elements for developing earthquake-resistant constructions. The
guideline provided below would be influential in assisting the authorities as well as designers of
buildings in developing structures that are earthquake sustainable. This technical report focuses
on the Nepal region to come up with designs that can preserve the local structures as well as
reduce the fatality rate in instances of earthquakes (Elghazouli, 2009).
Concerning gabble walls, the use of seismic belts has to be secure anchorage to the building
providing stable movement that is out-of-plane. When recent structures are considered, gable and
roof bands have to be put up and in structures that are being built need two gables to be fixed that
are cross-braced (Yeats, 2015). Additionally, vertical reinforcement can be used in masonry
walls. These reinforcements improve wall-bending features in strength hence controlling
horizontal cracks. This reduces the possibility of walls collapsing. Also, this reinforcement helps
in boding roofs to walls by providing controlled shaking and wall support (Waugh, 2017).
WWM reinforcement has to be connected to being installed in an L-configuration outside the L-
type wall-to-wall junction with the type T junction also being configured on the outside as
depicted in the figures below. The belt is located 300 mm below the level of the plinth and
continues to the level of the roof. When rubble walls are used, in situ RC shear connectors with
bars that are L-shaped are installed to increase reliability. These hear connectors are to be placed
150 mm from the level of the floor at 600 mm apart. These connectors are placed alternately on
the connecting walls (Ying, 2018).

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It is possible to use belt encasement round building openings. Typically, masonry walls have
piers installed in their openings. These piers are located below and above these openings. In the
occurrence of an in-plane motion, the involved walls would rack or rock diagonally beginning
from the corners that are open (Correia, et al., 2015).
Other than the use of the above methods, wall stiffening can be applied by using bamboo
reinforcement. This system of reinforcement involves strapping of bamboos wit added chicken
wire mesh. The used bamboos are mounted horizontally and vertically to the walls for prevention
of debris collapse. This reinforcement has been researched and used in Australia to prove its
significance in restraining falling debris. Also, there is an inclusion of timber beam rings. The
vertically laced bamboos are connected to the timber ring by being nailed. This connection
ensures absolute wall support. Such a technique has advantages such as simplicity and reduced
design-invasion for the local builders (Brebbia & Ivorra, 2017).
External cane and rope mesh could also be applied. This reinforcement system involves the use
of vertical cane that is being tied with horizontally running ropes to form 450 mm square mesh.
The developed mesh is used for wrapping round adobe walls as indicated below. One model of
this nature was inspected by using shake table resulting in cracked but restrained debris (Zhang,
et al., 2017).
In the endeavours of strengthening floors or diaphragms, diaphragm stiffening would be applied
by a number of various ways. This includes using steel strap installation. These steel straps are
connected to the walls’ exterior to the floors made of timber. Such a connection is achieved by
not using nails but bolts. In situations that floor beams are found to be parallel to the wall’s
exterior, straps that are V-shaped are connected to the floor before being connected to the floor.

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Sufficiently long straps in these timer floors have adequate tension capacity. The strap thickness
should be about 3 – 5 mm (Waugh, 2017).
Also, one may opt to use new exiting floor’s RC topping casting. RC topping that is 4 mm thin is
used in reinforcing placed mesh on these floors or roofs that already exist. The concrete topping
and timber floor connection have to be secured properly using nails. One more way that
stiffening could be influential is by using new timber planks installation. The planks of timber
are installed in layers that are perpendicular to the planks that already exist before nailing them
to the floor (Ying, 2018).
In sloppy roofs, the slanted roofs are majorly made of timber, clay tiles or purlin. The integrity of
timber roofs is improved by using nails o straps to tie their components. The recommendation
below have to be noted; maintaining a 200 mm mesh continuity overlap in corners or elsewhere,
use of galvanized binding wire for tying rafters of roofs using nails to the eave’s belt level. This
is to be done before the mesh is plastered. Also, there has to be of brick and stone walls,
chiselling or drilling 75 mm holes is easier. Steel wires that are 3 mm are used to replace nails.
These wires are passed through to hold and clamp longitudinal wires that are 450 mm c/c (Ying,
2018).
With all these proposed designs, I would like to conclude by outlining the following
recommendations. Rigid structures would tend to crumble when hit by earthquakes. It
recommended developing taller structures since they are more flexible than shorter buildings.
Constructing shorter buildings to sustaining an earthquake would mean increasing the level of
reinforcement compared to tall buildings (Engineers, 2007).

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Also, construction materials used in buildings are possible to contribute to reducing earthquake
damages. Some of the materials that can be considered in include wood and steel that pose better
flexibility compared to unreinforced concrete, masonry or stucco (Correia, et al., 2015).
Creation of buildings and structures by strategic addition of beams would help in the transfer of
energy in buildings that sway in instances of earthquakes. The base of the building, therefore,
gets the energy that is transferred to the ground, avoiding structural failure. Reinforced beams
and trusses help prevent structural warping and collapse.
Special designs can be made in foundations of buildings existing in earthquake-bound areas to
limit the damage that may be imposed. Plates in layered foundations can be added to buildings
for allowance of sliding movement. The result is a stable base throughout the movement of the
structure. Use of flexible cushions also helps in movement absorption as well as energy from the
earthquake (Engineers, 2007).

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References
Brebbia, C. & Ivorra, S., 2017. Earthquake Resistant Engineering Structures XI. illustrated ed.
Adelaide: WIT Press.
Correia, M., Lourenco, P. & Varum, H., 2015. Seismic Retrofitting: Learning from Vernacular
Architecture. 1 ed. Adelaide: CRC Press.
Elghazouli, A., 2009. Seismic Design of Buildings to Eurocode 8. illustrated ed. Perth: CRC
Press.
Engineers, A. S. o. C., 2007. Seismic Rehabilitation of Existing Buildings. 1 ed. Hervey Bay:
American Society of Civil Engineers.
Waugh, L., 2017. Recovering from Catastrophic Disaster in Asia. 1 ed. Tamworth: Emerald
Group Publishing.
Yeats, R., 2015. Earthquake Time Bombs. illustrated ed. Perth: Cambridge University Press.
Ying, E., 2018. Building Bottom-Up Health and Disaster Risk Reduction Programmes. 1 ed.
Townsville: Oxford University Press.
Zhang, Y. et al., 2017. Earthquakes and Multi-hazards Around the Pacific Rim, Volume 1. 1 ed.
Tamworth: Birkhäuser.