Your house is not along the faultline. What now?

[Image from tulisanes.wordpress.com]

A friend linked to this blog article:

http://tulisanes.wordpress.com/2012/04/03/is-your-house-standing-on-an-earthquake-faultline

Obviously, the author has good intentions, although he is seemingly not an engineer (or maybe still a young engineer?). The impression I'm getting though is that the article is suggesting to check whether your house/property is along one of the published faultlines. If it is, you're obviously in danger. But it might also give the impression that if you are a good distance away, you probably shouldn't worry.

Response to students' questions on NSCP 2010 wind loading provisions

These are actually in the comments, but I thought I should promote them to a full post. The first asks about leeward wall pressures:

Are the values for the Leeward wall pz really constant with elevation?

Response to a reader question regarding using the NSCP for estimating wind loads on irregular shapes

A reader asked:

How would you evaluate the pressure coefficients for structures with irregular polygon shapes. An example would be those structures with a plan shape resembling the letters "W" or "K." Most of the pressure coefficients in the code are for uniform cross-sections such as circle, rectangle, square, and so on. I have my own approach on this (mostly based on engineering judgement), but I would like to hear first on a wind load aficionado, such as yourself.

Response to a reader question on the damping estimation formulas in NSCP 2010 Section 207

A reader asked,

Equations 207-38 & 207-39 equate damping to 0.016/h and 0.23/h, respectively. However, Equation 207-40 equates damping to 0.007/n, in which h = height of structure, and n = natural frequency of the structure. Are Equations 207-38 & 207-39 correct, or should h be replaced by n?

Another NSCP 2010 Erratum

This one is actually a question asked by a former student.. from back in 2010! She says:

I came across with Method 1 - Simplified Procedure, and in Equation 207-2, pnet=lambda*Kzt*w*pnet9, where pnet9, as given in the definitions, is the net design wind pressure for Exposure B at h=9m and Iw from Figure 207-3. I turn to Figure 207-3, and in the label of Figures 207-3 it states that it is "pnet (Exposure B at h=10m with Iw=1.0 and Kzt=1.0)". My question is if the Figure 207-3 is already the net design wind pressure (pnet) or is it the pnet9 (net design wind pressure)? Also, if the values are for a 10m high building or 9m high building?

Some NSCP 2010 Section 207 Errata

If you have been using the NSCP 2010 wind loading provisions (Section 207), you have probably noticed already many typographical and other errors. I have only started to look at it more deeply recently, and here are some I noticed (and that readers have also pointed out):

Reply to a reader question on IBC vs ACI minimum reinforcements + New URL / Web Address

This RONJIE.COM Civil Engineering website has a new URL (or web address): engg.ronjie.com.

A reader read through my article about the UBC and IBC seismic provisions, and posted a question-comment not related to seismic provisions though, and this time talking about ACI and IBC minimum reinforcement provisions for concrete.  My reply and the original comment is shown below.

Designing for near-field earthquakes, using the NSCP 2001

If you are familiar with the NSCP 2001 earthquake loading provisions (ELPs), you know it is based on UBC 1997.  Some people think it is "copied" from UBC 1997, but copied "poorly."  It is not copied!  It is based on UBC 1997 but it had to be suited to "local" conditions.

Anyway some of the features of the NSCP 2001 ELPs that are in contrast with similar ones in the UBC 1997 are as follows:

UBC or IBC? Revisiting the justifications for moving from UBC to IBC as basis for new NSCP earthquake loading provisions

UPDATE: Please refer also to my newer article entitled, "Designing for near-field earthquakes."


1. Introduction

The National Structural Code of the Philippines (NSCP) has been the primary code that provides guidance to civil and structural engineers on the design and evaluation of buildings, towers, and other vertical structures around the Philippines since its first edition was published in 1972 (then as National Structural Code for Buildings or NSCB). It includes provisions for steel, concrete, timber, and masonry design as well as for estimating combined effects of dead, live, earthquake, wind, and other loads.