Pre-ozonation of industrial wastewater and subsequent biological treatment

Abstract

opulation in urban areas is alarmingly increasing due to rapid urbanisation. This in turn increases the density of population that results in close construction of buildings. The phenomenon of interference is ineludible and is certain in all residential, industrial and hilly terrains. Due to heavy loads and the non-availability of suitable construction sites in hilly terrains, engineers are often required to place footings at close spacing. These footings influence each other, effecting the load-settlement and bearing capacity behaviour. This influence of footings is termed as interference of footings. There can be the interference of two footings of the same building or footings of two closely spaced buildings. Hence the present research is on inspecting and analysing the behaviour of footings due to interference effect on sloping grounds with special emphasis on bearing capacity of the footing. The isolated footings are usually designed to satisfy one of two criteria that is no violation of any of either shear failure (bearing capacity) or maximum allowable settlement specified by the project based on the function of the building. But the footings on sloping grounds are also designed considering the slope failure. Hence, lot of parameters that influence the interference of footings on sloping grounds has been discussed in the present report. The problem is studied using finite element method. Numerical modelling and analysis were carried out using finite element method based PLAXIS 3D and the results were discussed. Parametric study is carried out by varying the geometrical properties that influence the interference phenomenon for both simultaneous and staged application of loadings. This report illustrates and describes the mechanism of interference of footings on sloping grounds and also effects of setback distances, inclination of slope and spacing between two adjacent footings on interference phenomenon. The interference between footings is observed to cause an increase in bearing capacity and decrease in settlement with reduction in spacing. Important changes in bearing capacity and settlement characteristics occur when a footing is placed in close proximity of a loaded footing. Behaviour of soil-structure due to interference phenomenon under dynamic loading is also studied by analysing the variation of lateral displacement of footings when the loaded footing is placed in close proximity of the study footing. A total of 16 laboratory scaled model tests were conducted on sloping grounds for different S/B and b/B ratios. It was found that bearing capacity of the footing increases with reduction in S/B. The bearing capacity is found to be maximum at S/B=2 where the soil between two footings gets confined and behave as a single large footing.