Evaluation of dynamic properties of soils in site for proposed petrochemical plant in Edo State, Nigeria

In geotechnical engineering, the problem of dynamic loading of soils and soil structure interaction system requires the determination of the dynamic properties of soils. The determination of the dynamic properties of soils deposit is of uttermost importance in studying site response to dynamic loading and the probability of seismic hazards occurring. In this study, a plate load testing equipment was designed and constructed at the faculty of engineering, university of Benin. A full scale field testing programme was then conducted under static and cyclic loading condition on three different points to determine the bearing capacity of soils and the dynamic response of the soils under various loading conditions. In the case of the cyclic plate load tests, settlements of the base plate for both loading and unloading conditions were recorded. The results of the static and cyclic plate load tests were used to plot load-settlement curves for each point where the test was conducted. The graphs for the load against elastic settlement represented arithmetical graph from which the line of best fit were obtained. From the results, it was found that for the three tests point the load required to cause settlement of 2.5mm were 104.3kN/m2, 83.27kN/m2 and 62.96kN/m2 respectively. The soil bearing pressure for a permissible elastic settlement of 25mm was estimated from the equation of line of best fit as 630 kN/m2. The dynamic properties of the soil were also computed for the three locations. The results show that the soils around the site is stable and can withstand the effect of the anticipated plants vibration during construction and during operation of the plants. The study of dynamic properties of soil is essential as they are very important for dynamic responses and dynamic analysis of major structures and sensitive machines and equipment in a site such as the petrochemical plant.