Earthquake Resistance Vernacular Architecture

Earthquake Resistance Vernacular Architecture Ankita Mehta (2GI11AT008, V SEM B.Arch.)

Shraynita Paliwala (2GI11AT046, V SEM B.Arch.)

Department of Architecture, Gogte Institute of Technology, Belgaum anya.ankita@gmail.com shraynita@gmail.com

Abstract - The trend towards creating a more sustainable built environment is quite established on the global scale. With the evidence that vernacular architecture has some of the remarkable features of sustainability with reference to seismic tremors, this study aims to examine Himachal vernacular settlement in the north of India in order to explore inherited experiences and knowledge of sustainability. The kath kuni style plays a major role in overcoming the seismic tremors. In Himachal Pradesh such sustainable environment can be found in buildings reflecting both the culture and the climate. Various factors such as economics, religion, ecology, family structures, and cultural interaction, affect the evolution of a culture. The lifestyle of building occupants, and the way they use their shelters, directly influences their building forms. Elements including form, orientation, layout, openings, and colonnade balconies, material are climate responsive which is in consonance with the ecological movement. The aspects of vernacular architecture are fulfilled by the locally available materials as they are hazard resistant to a great extent. They have a high degree of sustainability; they meet the global standards and explore global concepts.

Keywords— Vernacular Architecture, Himachal Pradesh, Kath Kuni Style, Climate, Culture, Sustainability.

I. INTRODUCTION What is sustainable architecture? Sustainable architecture is a general term that describes environmentally conscious design techniques in field of architecture. Also known as green architecture.

Activities aimed at promoting sustainable architecture are now underway in countries throughout the world. One aspect of this trend is the keen interest being shown in the high environmental performance of vernacular architecture. The term “vernacular architecture” is used here to refer to traditional buildings that have been designed and built to match the local climate and culture. Much research has been carried out on vernacular architecture, but mostly from humanities or social science perspectives, and very little from an environmental engineering angle.

Fig.1 Moroco’s atlas Kasbah eco-lodge

Fig 3 Round thatched hut Zimbabwe

Fig.2 National Park of Mali

Fig.4 Victoria falls safari lodge

The built environment is the interpretation of the traditions and the aspirations of the local people. Buildings thus reflect the cultural character of the people that live in them (Richardson, 2001). This is indicated by the planning, the way of building and the way of living. Vernacular architecture is presented in the classification of Hill architecture as one of the trends. It developed from the appropriate continuation of local traditions and sensitivity towards local conditions with a mix of external influences.

Buildings built with local materials by local residents using built-by-hand construction methods create a lasting architecture that is specific to place and culture. Vernacular architecture provides shelter and comfort with the evolution of craft passed down through generations. It is an epitome of place to which it belongs, cannot be imported from elsewhere.

II. MAJOR CHALENGES TO OVERCOME The negligence of the interaction between the resistant structure and other non-structural elements in the building modifies the resistance-stiffness relationship of structural elements. In such a situation, it is possible that the structure does not show all the resistant capacity at once as required

during the seismic action. This results in its partial damage or a total collapse. This is one reason for the pure structural analysis becoming insufficient to claim the seismic imperviousness of a building. Therefore, an additional approach becomes necessary, which may regard the seismic-resistant system as a whole, where all the structural, non-structural and spaceforming elements conforming a building are considered to be interacting with each other and hold responsible for the seismic-resistant capacity.

survive earthquakes for which the region has received in the past. There have been instances when tremors have dislodged the stones from the frame, and later, have been hammered back into the intact mesh of wood houses and temples in the style.

III. HIMACHAL PRADESH Major regions of Himachal Pradesh experience frequent and seismic tremors as it lies in high seismic hazard zone further leading to problems of soil erosion and landslides.

Hence limitations on the height of the building due to earthquake should be taken into consideration. The houses should be oriented accordingly on the hill slopes and existence of tall shoddy trees and dense forest area obstruct the winter sun required for the buildings. High cost is involved in the site development due to the cutting and the filling process to construct foundation. Non-availability and transportation problems of construction materials further adds to tribulations, as shown in Fig. 5.

Fig. 6 Technique of interlocking wooden sleepers and stones

Fig. 7 Layers of wood and stone. Fig. 8 Interior view of building technique.

Fig. 5 Seismic hazard zone map, India

IV. MITGATING SEISMIC HAZARDS To counter the seismic forces, the structures usually stand on a high solid plinth, made up of dry dressed stone masonry.

The huge mass serves as a dampener pad to the earthquake forces and the dry construction allows for vibration and hence faster dissipation of the energy.

The 'Kathkuni' or 'Kathkundi' style of building construction is something unique here. This style involves a clever technique of interlocking wooden sleepers and stones. A mesh of the wooden sleepers (usually cedar) is created first and then packed with dressed or raw stone. One of the characteristics of the structure is that it contains no vertical members. The structure therefore has an inherent elasticity and has been proven to

V. FACTORS INFLUENCING SUSTAINABLE VERNACULAR ARCHITECTURE Vernacular architecture is influenced by a great range of different aspects of human behaviour and environment, leading to differing building forms for almost every different context; even neighbouring villages may have subtly different approaches to the construction and use of their dwellings, even if they at first appear the same. The major factors influencing factors are culture, climate and materials.

A. Culture The Indian calendar months of Margasirᚣ(September), Pausa(October), Magh(November) and Phalgun(December) are regarded as auspicious for the start of construction in Himachal Pradesh. A majority of the population is engaged in agricultural practices whose main preoccupation was to store grains efficiently. The house which constitutes many stores was built for storage of grains which formed the back bone of the agrarian family.

1) Design Parameters: Ideally, the main aspect of the house should face east and the rising sun.The house has been

built such that the cow-shed and kitchen form a separate unit, away from the living quarters. The living quarters basically include bedrooms and stores for storage of grains. As a general rule the houses do not have a boundary wall.

B. Climate Himachal Pradesh falls under Mountainous climatic zone having a great diversification in the climatic conditions due to variation in elevation (450-6500mtrs). It varies from hot and sub-humid tropical (450-900mtrs) in the southern low tracts, warm and temperate (900-1800mtrs), cool and temperate (1900-2400mtrs) and cold alpine and glacial (2400-4800mtrs) in the northern and eastern high mountain ranges.

1) Design Parameters: Due to the cold climate, the southern slopes are preferred for dwellings. The orientation of the houses is done in such a way so as to maximize the penetration of the sun rays as it will help keep the interiors warm. The path of the sun controls the height of building, as the sun is needed for each dwelling unit, as shown in Fig. 9.

C. Materials The typical house is constructed of clay bricks and the roofs are of slate. In some areas the slate roof is also replaced by timber. The locally available materials used for construction purpose are: 1) Deodar Wood: It is one of the strongest Indian conifers which impart stability to tall structures. This wood is insect and termite resistant and even when untreated, can withstand long periods of weather corrosion. It is used in making posts, beams, window and door frames, shutters, roofs etc. This wood is advantageous as it is soft and easy to work in absence of high tech tools. Its properties were understood priorly and its texture and scent have been prized for ages.

Fig. 9 Orientation of the houses to maximize the penetration of sun rays.

Fig. 11 Deodar wooden truss supporting the roof.

Small window sizes and low ceiling height help in preventing heat loss and keep the interiors warmer. Site susceptible to high winds, storms, floods and landslides should be avoided, as shown in Fig. 10.

2) Hard Stone: These stones are obtained from local quarries and are used in building foundation and walls supporting the roof.

Fig. 12 Hard stone.

Fig. 10 Small window size and low ceiling height

Fig. 13 Stone used in walls.

3) Slate Tiles: Also known as metamorphic rocks are used in roofs of the buildings. These have high quartz content, frost resistant, absorb heat and provide a moisture barrier to the

structure. Terrace in all around the building should have proper slope for efficient drainage, in heavy rain fall and snow fall areas, as shown in fig. 14.

Fig. 14 Slate Tiles used in roofs of the buildings.

Fig. 16 Front Elevation

V. FACTORS REFLECTED IN PLANNING A. Plan Layout: Fig. 15 shows a typical example of a dwelling in Himachal Pradesh, where it is divided into two sections by a common passage. The basic idea of segregating the service area from the main spaces was to maintain hygiene.

Fig. 17 Side Elevation

C. Sections The structure is a two storey building with an Attic. Low Height of the rooms (2.1 – 2.4 m), keeps interiors warmer from heat released by individuals, also low surface to volume ratio reducing heat loss from surfaces.(refer Fig. 18) Fig. 15 Plan layout

B. Elevations The sloping roof, as seen in the traditional dwelling, is a common feature in all the houses in the area due to the compact planning of the house, as shown in Fig. 15, Fig. 16, and Fig. 17.

Fig. 18 Section

D. The Attic An interesting part of the house is the attic as it acts as a multifunctional space. It is used to store grain which forms the staple diet of the people and is also served as abode of the god.

The two windows on the sides ventilate and dry the grain at the same time protecting from the rain. Although the main function of the attic is to insulate the house, it serves as an excellent storage space, as shown in Fig. 19.

Fig. 19 The Attic

E. Building materials

Fig. 21 The timber truss which makes the first floor roof is effective in insulating the house as well.

Timber ladder is used to go to the attic where the corn is stored. The staircase used to reach the first floor of the house is made of timber, with stone slabs also introduced, as shown in Fig. 18.

F. Built form (Paper Model) The built form of the house constitutes about 60% of the plot area. The house in its totality, as seen from south side, forms a compact unit. As a general rule, the houses do not have a boundary wall, as shown in Fig. 20, Fig. 21.

Fig. 20 South side view

Balconies provide a good sun-space or solarium to perform various activities during day time, as shown in Fig.17

VI. CONCLUSIONS Vernacular architecture is an area of architectural theory that studies the structures made by empirical builders without the intervention of professional architects. Himachal Pradesh here reflects sensitivity to local culture mainly by adopting the locally available materials to provide stability as well as sustainability to the entire structure. The approach to the kath kuni style is the result of the building being considered as a whole in which every component interacts with each other during seismic activity. This interaction may be either positive or negative. Consequently, the analysis of such interrelations and their compatibilization from the architectural design viewpoint is required to prevent a decrease of the building seismo-resistant capacity.

The final conclusion not only stresses on the need for carefully planned spaces that are capable of controlling people’s behavior but at the same time takes into consideration the local traditions and the environment hence fulfilling their basic needs. Nevertheless very important principles and components can be learned from this heritage, to be applied, in sustainable architecture.

ACKNOWLEDGMENT We avail our opportunity to thank our Principal Prof.

Dr.A.S.Despande and HOD Ar Nishita R. Tadkodkar for encouragement of the Paper Presentation in Avalanche.

We are deeply obliged by the support and guidance of our Prof. Ar Shruti R. Kamat, Ar Rupali D. Kavilkar and Ar Jyothi S Patil.

We thank teaching, non-teaching and technical staff of our department for their support.

This Paper is incomplete without the blessings of our parents and good wishes of friends .

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