Model Studies on Bamboo-Geogrid Reinforced Fly Ash Walls under Uniformly Distributed Load

Due to ever increasing urbanization and industrialization, the demand for power and electricity increases at a staggering rate. In order to address the demand for electricity, more advanced and productive thermal power plants are coming up and being installed in different parts of the world. As a consequence, the generation of fly ash in large quantities as a by-product from coal-burning electric utilities has become a problem. Use of this material in construction that can consume a large volume will not only solve the disposal challenges bulk presence of fly ash, but also offers the benefit of both protecting the environment and acting as an economic alternative to traditional materials. This paper presents laboratory model tests performed on unreinforced and bamboo-geogrid reinforced fly ash walls under uniformly distributed load. The effect of the ratios of length to height (${\mathit{L}}_{\mathit{r}}/\mathit{H}$), vertical spacing to height (${\mathit{S}}_{\mathit{v}}/\mathit{H}$), and coverage (${\mathit{R}}_{\mathit{c}}$) of bamboo-geogrid reinforcement on settlement of the backfill, horizontal displacement of the facing, and failure surcharge pressure (q) was studied systematically in a series of model experiments. It was observed from the results that inclusion of bamboo geogrid (mattresses and strips) generally improved the overall behavior of the reinforced fly ash walls when compared with unreinforced fly ash walls. For example, at ${\mathit{S}}_{\mathit{v}}/\mathit{H}=0.2$ and ${\mathit{R}}_{\mathit{c}}=1$, $q$ was improved 2.47 and 3.44 times for ${\mathit{L}}_{\mathit{r}}/\mathit{H}=0.35$ and 0.65, respectively. Only doubling ${\mathit{S}}_{\mathit{v}}/\mathit{H}$ to 0.4 improved the $q$ values 1.98 and 2.81 times for ${\mathit{L}}_{\mathit{r}}/\mathit{H}=0.35$ and 0.65, respectively. Generally, increasing the length of reinforcement and coverage ratios and decreasing vertical spacing played a vital role in influencing failure surcharge pressure, backfill settlement, and lateral displacement of the facing. However, further research on a large scale or under field conditions is required for practical applications.