Shock Safe Nepal: Validation of the model house and a long-term plan for sustainable upscaling of earthquake resistant housing in rural areas in Nepal

Abstract

Shock Safe Nepal was founded as a response to the 2015 Nepal earthquakes to function as a platform to contribute to the development of knowledge on earthquake safe housing. The goal of the report of team 5 is to validate and optimise the design of the pilot house that was created based on the work of previous teams, and the development on implementation plans for a validated and optimised house. Literature study, field work and interviews have been performed resulting in main findings of this report.Primarily, the used materials were analysed in the report, including bamboo, CSEB bricks and concrete. They were analysed consulting literature, conducting laboratory tests in cooperation with the University of Tribhuvan. Bamboo was mainly analysed consulting literature sources, since laboratory tests were not feasible. It was found that its material properties are immensely difficult to determine and can vary from one column to another. However, it remains a strong and cheap building material. CSEB bricks were used due to its availability, strength and price. The material properties were derived from tests done by Build Up Nepal and from literature sources. Its mechanical performance is like that of concrete. It’s an easy material to build with and incorporate steel rebar’s. However, its durability and consistency is something which was not thoroughly investigated and remains debatable. The concrete used, was thoroughly tested, conducting slump cone, compression and Schmidt Hammer tests. It was found that the concrete used in the pilot house is of acceptable quality, but there is room for improvement by following clear guidelines and technical assistance. Subsequently, static calculations were executed, regarding the roof, the load bearing structure and the foundation. It was found that these different components, perform safely under static conditions, with the applied loads, separately and combined. The load bearing structure has turned out to be a wall-bearing structure. This was not assumed at first. Furthermore, after calculations, it was found that the roof and foundation were largely over dimensioned. This is, however, determined considering many assumptions, such as the soil properties.Regarding an earthquake situation, the walls and bearing capacity were researched and calculated following quasi-static conditions. The earthquake conditions were derived from the Peak Ground Acceleration. Primarily the walls were researched. Two scenarios were considered, a 3-point collapse failure mechanism and punctual overturning collapse failure mechanism. Both mechanisms were tested for different wall compartments. These calculations give a small insight in the actual situation, because dynamic loads are applied statically, non-linear or dynamic calculations should be conducted as well as FEM modelling, for more thorough understanding. It must be said that the rebar and resonance effects were not considered. Regarding the bearing capacity, a PGA of 0.6 was used and from calculations, partly considering the soil and superstructure inertial effects, the bearing capacity would not fail. However, superstructure resonance was not considered. Larger PGA’s were not investigated, which means that it is not determined under which conditions failure would occur. From these analyses the Structural optimisations are made to the design. This includes improving the joints between different elements of the house. Regarding the materials used the optimisations include 5 protecting the CSEB bricks from weather as they are load-bearing. Guidelines are given on the placement of the house regarding the foundation and the slope. According to the calculations the foundation is over- dimensioned.For the stakeholder analysis, extensive research was done through interviews which was combined with literary information available. This was then used to create a power interest grid and a network analysis, which shows the links between different categories of stakeholders and different specific stakeholders. This analysis also gave insight in the sheer number of stakeholders involved in rebuilding Nepal and the importance of defining the role of SSN further. The external factors that are important in working in Nepal were analysed, this was done regarding social, technical, economic, environmental, political, legal and ethical aspects and based on literature research, field research and interviews. Implementation methods of different types of organisations in Nepal were analysed. These findings were concluded in a SWOT analysis of the organisations. Defining the strengths, weaknesses, Opportunities and threats of other organisation help to define the direction that SSN should move in and those aspects of building in Nepal that can also be defined as strengths, weaknesses, opportunities and threats to SSN or make SSN different to other organisations. The risks of building in Nepal must be considered to create a realistic and feasible long-term plan and need to be mitigated a risk analysis is done. The findings in the risk assessment are found in external risks, design risks and construction risks. A plan is then set up to mitigate external risks and construction risks are the. The findings of the long-term plan are organised into a strategy for SSN, an engagement plan and an implementation pathway. The strategy is concluded in a SWOT analysis which is then used to create a TOWS analysis. This TOWS analysis combined the internal and external strengths and weaknesses to bring new creative ways of maximising strengths and opportunities and minimising the weaknesses and threats. The Implementation pathway contains long- term goals for SSN, that are structured into regulatory, implementation, technical and organisational goals and that can be added onto by future teams.This research is to be a logical step in a series of research projects which will contribute to the reconstruction of an earthquake safe environment in Nepal. It can be used as consultation advice, guideline or as a base for in-depth follow up research on one of the included topics.Shock Safe NepalCIE4061-09 Multidisciplinary Projec