A note on the structural system and progress at Dr. Bhavesh Dave’s residence at Kensville

The Kensville site is located just before the great marshes of Nalsarovar bird sanctuary on a natural drainage path, and therefore has a high water table. This geological / geomorphologic feature has led to foundation soil being dominantly of silty sand type. Approximately, seventy five percent (75%) of the soil is grainy and rest is highly shrinking clay. In colloquial terms*, the soil is also known as black cotton soil. The soil is highly draining in nature besides its average bearing capacity. This soil condition along with existing loads required us to consider a circular masonry foundation, on which the ferrocement shell and landscape grass composite would rest.  It is intended that enough integrity is achieved by the foundations and the superstructure shell independently, which then would account for differential movement conditions because of the soil. See the sketch below for details.

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Construction of this masonry foundation is complete and the floor plinth is being readied now.  Like other parts of the country, availability of qualified workforce is a concern, and the site’s remoteness keeps the pace of our work slow. However, our contractors Nirav and Dakshesh found local workforces proficient in brick masonry and excavation. Soon after completion of excavations, constant interaction with the brick masons, before starting the work and during execution, ensured desired quality.


For pictures click 


At present, mobilization of materials for construction of ferrocement shell is underway; and we will keep uploading information here as work progresses. Please keep visiting.

*black cotton soil is a local technical simlie for highly shrinking clay

18th September 2011 Earthquake

Update: 29th April 2012
The progress at Sangkhola school is slow but strong. The slow progress is largely due to non-availability of qualified workforce which can work with Reinforced Cement Concrete (RCC ) as a construction material. The State Education Department has also expressed its desire to construct new buildings using RCC only, and is keen that the work is completed at its earliest. It is well understood and established that the damage during this earthquake has been primarily due to badly retained earth, retaining walls, and inadequate designing, especially of RCC joints. In many cases the soil wasn’t properly compacted; in some cases soil has been just dumped from other places in creating levelled land and is therefore very loose, and retaining walls were inadequate for the soil and therefore the building they were supporting. Due to the insufficient loose foundation soil, the structures underwent more shaking and resulted in greater damage despite Sikkim’s buildings having relatively good construction quality. Inadequate attention to design therefore seemed to be an important reason for the extensive damage caused by the earthquake.

Now, with a revised project plan we are expecting foundation work to complete by mid May; and structural skeleton with other finishing works envisaged to complete by the middle of June. See pictures of the foundation work here, where present emphasis is on preparing highly compacted foundation trenches to support RCC column pedestals.

We are looking at building the local contractor's competency in both technical and managerial aspects of construction. This made us put more experienced engineering team on the ground with Rakesh from SEEDS in the lead now along with the mason Ramesh from Patanka village in Gujarat, to facilitate the re-construction of the school.

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In addition, preparations are underway for reconstruction of the damaged buildings in three school campuses in the East district of Sikkim. We are additionally looking at overall Life Safety in these school campuses for future extreme events, and improvement of the local built environment of through awareness building and community participation exercises.

Sikkim updates-18'th September 2011 earthquake

Update: 4th Feb. 2011

Due to some administrative hiccups we had to change our chosen school. This time, after surveying some more government as well as private schools, we could find Sangkhola primary school, which is located some 20 kms before the state capital Gangtok on National Highway 31A .

The SEEDS team of Rakhee, Rahman, Harjeet, and Rinkoo is working tirelessly on the ground to design for reconstruction of the school building in Sangkhola. The aim is not only to put structures that are safer than before, but also has a built environment fabric more conducive to learning.

The team is in regular consultation process with the Local village population, Panchayat, and various government departments, especially HRDD (The State Education Department). These informal workshops have been very successful, please see pictures later, in evolving design alternatives for the new school building. Sooner, as the construction gears up we will be in a position to conduct community workshops as well as some hands on interaction sessions aimed at Engineers and Masons.

Some photographs of damaged state of Sangkhola school is shown in the Picasa Album here below

120204SangkholaDamage

Some design alternatives are shown in the Picasa Album here below

120204SangkholaNewDesignAlternatives

Some of our recent assignments

While this has been Quakeschool’s first year in a seemingly tough home environment, India, there were some useful lessons, rather these were reminders. The work has been reflective, mostly reinforcing the fact that efforts put in reiterative engineering, wherever it is carried out, help bring down project costs significantly. These efforts also lead to simplicity in design and its execution. At the same time, we also tried to understand the term sustainability in our projects.

We recently concluded some task-based assignments for a few of our new clients. Three interesting ones among these were-

1. Design for foundations of a solar plant in Samakhyali, Gujarat <link>

2. Design analysis of a bamboo structure in Nagpur, Maharashtra <link>

3 . Value engineering analysis of a ground-plus-ten-storied structure in Ahmedabad city, Gujarat <link>

The Samakhyali project is an upcoming electricity generation plant being run on solar energy. One of the important components is the plant’s structural foundation on which its panels and assembly will rest. The project was an opportunity for us to work with mechanical and instrumentation engineers from the US and India, where as a team we worked together to optimize the size of these foundation units, six thousand in numbers, hence also reducing costs. More on this project can be found at this link.

A completely different structural design work was an exercise with Wondergrass that introduced us to one of the fifteen species of the bamboo family used in housebuilding, called Dendrocalamus Strictus (or simply D. Strictus). We tested structural adequateness of this bamboo in a typical housing unit designed by Wondergrass. We also again learnt that although significant avenues in rural areas as well as government policies exist in India to promote bamboo as a housing material, it is still not being exploited to its fullest. A key reason for this being most people, including researchers and building practitioners, perceive bamboo as a non-durable and obsolete material; and more so for house building on a large scale, hence overlook the versatility it offers as an alternative material. For details of this project please visit this link.

Through the ground-plus-ten-storied structure project, we conducted a computer based 3-D analysis of a typical high rise building in Ahmedabad city. This high rise structure is made of cement and embedded steel for extra tensile strength, which are most expensive of these materials. This type of construction can be seen in almost all developing countries because of the flexibility its primary ingredients—cement and steel—offer. Engineering in a way is for ensuring safety and reducing costs, and here our aim has been to analyze this structure from a ‘value engineering perspective’, so we could reduce its cost by checking consumption of its basic ingredients. Project’s details can be found here on this link.

In executing these small projects, we realized that whatever be the scale of building structures we design, or the material we use, if intelligently engineered will not only bring down the costs but can help in addressing the issues of sustainability as well, which has societal and economic at their own levels.