دانلود رایگان مقاله انگلیسی مطالعات تطبیقی در مورد ظرفیت باربری پی های کم عمق در شن از N و φ - اشپرینگر 2017

Abstract

This work presents a comparative study on the bearing capacity of strip, square, circular footings and raft foundations in sand, estimated from the standard penetration resistance, N, and the angle of shearing resistance, /. The net safe bearing capacity estimated directly from N using Teng’s equation is compared with that obtained from / as per IS:6403. Likewise, the net safe settlement pressure determined from IS:8009 (Part 1), based on N, is compared with that attained from the semi-empirical approach of Schmertmann et al. A parametric study quantifies the effects of the standard penetration resistance and the size and depth of foundation on the net safe bearing capacity and the net safe settlement pressure of strip, square, circular footings and raft foundations in sand. Interactive charts are prepared in terms of the standard penetration resistance to highlight the appropriate method for the benefit of civil engineers.

Conclusions

Based on the results obtained from the comparative analytical study on bearing capacity of shallow foundations in sand from N and /, the following conclusions are drawn:

1. The net safe bearing capacity of strip and square footings, for Df/B B 1.0 and N = 10–40, and circular footings, for Df/B B 1.0 and N = 10–25, in sand, can be estimated directly from N using Teng’s equation, without having to do so from / as per IS:6403.

2. Teng’s equation and the equation of IS:8009 (Part 1), both based on N, can be used to estimate the net safe bearing capacity and the net safe settlement pressure, respectively, of strip and square footings in sand corresponding to a given Df/B ratio.

3. For determination of net safe settlement pressure of circular footings in sand, the equation specified by IS:8009 (Part 1) is a conservative option over that of Schmertmann et al.’s approach.

4. The equation of IS:6403 based on /, and the equation of IS:8009 (Part 1) based on N, are suggested for estimation of net safe bearing capacity and net safe settlement pressure, respectively, of the rafts under study.