Mathematical Model of Air Pocket Evolution during Water Filling a Long-Slope Pipeline and Its Application to Air Removal Prediction

During water filling a long-slope pipeline, air pocket is very likely to be entrapped at peak point. In order to track air movement and predict air removal conditions, a mathematical model of air pocket evolution, including its formation, compression, and entrainment, is proposed in this paper. The simulation results were compared with the engineering field data and the two are basically consistent. Furthermore, the two most important factors which play a great role in the removal of air pocket, i.e., the terrain category and the inlet flow rate, are analyzed in detail. It is concluded that the removal conditions reach three outcomes: air pocket compressed and partly removed, compressed and completely removed, and compressed without any removal. In this paper, the terrain which leads to the last outcome is called the “Dangerous Terrain.” And for the “Dangerous Terrain,” it is of great importance that the inlet flow rate should be strictly confined within a certain level. While for the other two categories of terrains, an increased flow rate is in any respect beneficial to the removal of air pocket.

Seismic and Wind Performance of Multi-storeyed Building with Plan and Vertical Irregularities

It is a big challenge that the tall buildings must withstand the various forces acting from different directions and aspects such as seismic and wind forces while designing the tall structures it is mandatory to deeply understand the seismic and wind behaviour of multi-storeyed buildings. In this study we are concerned to determine and analyse the seismic and wind behaviour of high-rise buildings some of which were regular and other had irregularities in them in their plan and elevations. Three G+30 storied buildings were considered which were situated in seismic Zone-V and analysis were carried out using response spectrum method as per IS 1893- 2016 on ETABS software. Each building is subjected to wind load at different terrain categories to examine its effects at different slopes as per IS 875 Part 3 2015.Various parameters like Auto lateral load, maximum storey displacement, maximum storey drift, overturning moment, storey shear and time period were considered in this study. It is concluded that vertical irregular building in terrain category-4 with ground slope less than 3 degree’s provides greater resistance against both seismic and wind loading among all buildings.

Analysis of Wind Effect on High-Rise Building for Different Terrain Category

This paper analyzed the effect of wind loadings on high-rise building for different terrain categories. The wind speed and design wind pressure for the different terrain categories adopted for this study were calculated as per logarithmic wind profile equation and BS6399-2:1997 respectively. Also, the nodal displacement of a 3D high-rise building model with reference to the calculated design wind loads were performed using finite element analysis software(STADDPROV8I). From the result obtained, it was shown that Terrain category IV when compared to other terrain categories recorded lower wind speed and pressure from the ground to a height of about 10m. The writers also observed that at greater terrain category(TC4), the wind speed and pressure tends to be much higher at the top floors(10m-48m) of the high-rise building whereas, terrain categories (TC3, TC2, TC1) recorded lower wind speed and pressure at that same height(10m-48m). this disparity however was discovered to be due to a phenomenon known as gust effect. Also, the nodal displacement for the different terrain category (TC4, TC3, TC2 and TC1) on each floor of the high-rise building increased uniformly in respective pattern as the height of the 3D model increases. In conclusion, the authors therefore remark “the greater the terrain category, the lowest is the wind speed in the roughness sub layer and the longer height it takes to reach gradient wind speed”.