A REFERENCE FOR THE ALLOWABLE SOIL BEARING CAPACITIES IN QUEZON CITY, PHILIPPINES

Abstract

Quezon City is the largest city in the National Capital Region of the Philippines. This city has several other cities and provinces that bound it. North Caloocan and the province of Bulacan bound the northern portions of the city. The eastern side of the city is bounded by Marikina city, the city of Manila and the province of Rizal. Mandaluyong, Pasig and San Juan bound the southern portions of the city. And finally, the western portions of the city are bounded by the cities of Valenzuela and South Caloocan. This paper provides the estimated allowable soil bearing capacity at different locations within the city. The allowable soil bearing capacity is being used by structural engineers when determining the required sizes of the shallow foundation for the structures that they are going to build. Several borehole data were collected to estimate the geotechnical parameters. The geotechnical parameters such as the angle of internal friction, cohesion, and unit weight were estimated using the SPT values derived from the collected borehole data. These geotechnical parameters were then used to estimate the allowable soil bearing capacity using Terzaghi equation for bearing capacity. The final output is a map of the city showing the contours of different colors which correspond to the different values of the allowable soil bearing capacities. Due to the presence of Guadalupe tuff formation at shallow depths, the estimated allowable soil bearing capacity ranges from a low od 100 kPa near the ground surface to as high as 1000kPa at a depth of five meters.