Archive for the ‘Engineering’ Category

Without basements, Joplin had scant refuge from tornado

Wednesday, June 1st, 2011

For years, I have been preaching the value of basements, especially in stormy weather.  When the tornado blew threw Saint Louis on Good Friday, there was a lot of damage, but no deaths.  Saint Louis is a basement city, where basements are the norm, not the exception.  A mere three hundred miles down the road, a tornado rips through Joplin, killing over 130 and becoming the deadliest single tornado since 1947.  Yes, the Joplin tornado was an EF-5 as compared to an EF-3, but no deaths versus over 130?  The stark contrast isn’t the strength of the tornadoes, but the presence of, or lack of, basements.  Even Reuters has picked up on it-

Reuters 
By Kevin Murphy Kevin Murphy Tue May 31, 5:43 pm ET

JOPLIN, Mo (Reuters) – Like a lot of other Joplin homeowners, Herndon Snider rode out the May 22 tornado in a bathtub. Other popular places to take cover from the vicious tornado were closets and center hallways.

Such is the price people pay for living in communities such as Joplin where basements are rare due to rocky, wet soil.

About 82 percent of homes in the Joplin area have no basements, according to the Jasper County assessor’s office.

The vulnerability of residents to injury or death in tornadoes for lack of a basement has drawn attention to the need for more storm shelters for individuals or large groups of people.

“I’ll bet there will be a lot of them built here,” Snider said.

The EF-5 tornado has been rated the deadliest single twister in the United States since 1947. The official death toll was 139 as of Saturday.

Joplin Fire Chief Mitch Randles saw first-hand what a tornado can do. The twister destroyed his house, which has no basement. Nobody was home at the time.

“My wife told me we are never going to own a home without a basement or storm shelter,” Randles said.

Digging basements in most of Joplin is impractical and cost-prohibitive because of a high water table and limestone just below the surface, said John Knapp, professor of geophysics at Missouri Southern State University in Joplin.

Unfavorable soil contributes to a lack of basements in much of the South, where just over 11 percent of new homes include full or partial basements, according to a 2009 survey by the U.S. Census Bureau.

By contrast, more than 77 percent of new houses in the Midwest and Northeast had basements, the survey found. In the West, 21 percent of new homes had basements.

The percentage of new homes with basements has dropped steadily in the last 20 years, probably due to cost, according to Crystal Harrington, executive officer of the Homebuilders Association of Southwest Missouri.

Nationally, 42 percent of new homes had basements in 1992, according to the Census survey, compared to 30 percent in 2009.

Knapp said northern U.S. residents can thank glaciers for their basements. Glaciers left a deep layer of topsoil in regions generally north of the Missouri River. In Kansas City, just 160 miles north of Joplin, more than 90 percent of homes have basements, according to county assessors.

Safety officials note basements do not guarantee safety in a tornado because the house can collapse and trap or injure occupants. But many people killed in the Joplin tornado were swept from their homes, which would be less likely if they were in a basement.

Mayor Mike Woolston said that “in an ideal world” shelters would be accessible quickly throughout residential areas, but he said they are hard to justify because major tornadoes are still a rare occurrence.

Randles said the 20-minute tornado warning most of Joplin received on May 22 was unusually long and six or seven minutes are more common, leaving little time to reach a shelter.

“You’d almost have to have one on every block,” Randles said. “By the time you found your car keys and got going, the tornado would be there.”

Keith Stammer, emergency management director for Joplin and Jasper County, agreed.

“An attempt to move to other locations would risk placing people in danger,” Stammer said.

The Federal Emergency Management Agency has funding available to help pay for putting shelters in public buildings, such as schools and government structures, said spokeswoman Susie Stoner.

The alternative to community shelters is for individuals to put shelters in their homes. One such shelter is called a safe room, typically a concrete-reinforced master closet or laundry room, said Harrington.

Another alternative is a poured concrete, above-ground structure in the shape of a vault that is often put in a garage, she said. Those structures typically cost as little as $2,000 and were growing in popularity even before the recent tornado, she said.

“It’s an absolutely viable product right now,” Harrington said.

(Editing by Mary Wisniewski and Jerry Norton)

(This sory was corrected in the third paragraph to reflect revised calculations by the Jasper County assessor’s office)

Now, I must take exception to something that was stated in the article, namely the unsuitability of Joplin for basements.   Except in bogs, swamps, or floodplains, basements can pretty much be built anywhere.  Springfield, Illinois, has a high water table, but basements are common, thanks to sump pumps.  If you take a vacant chunk of land with a high water table, and build on it a bunch of houses with basements and sump pumps, over time that water table will be lowered, thanks to the combined efforts of all the sump pumps.  If the Aztecs can build a city on a lake, I think we can build basements in areas with high water tables.  As for the limestone, limestone can always be dug or broken or blasted out.  Yes, to build basements in less than ideal areas is not cheap, but it can be done, and it should be done.  Is one human life worth the cost of a basement?  I don’t think it is, but then I am just naive.

93th Street No More!

Thursday, May 19th, 2011

When I showed the picture of the “E 93TH ST” sign to my sign fabricator, he was horrified that such a sign was out on the street.  Before he left for the day yesterday, he peeked his head in my office and proudly informed me that he had fabricated the correct sign, and it was to be hung in the morning.  And it was.

I am now the proud owner of the “E 93TH ST” trophy, and I promised my fabricator that I will give it to him as a present for his retirement.  When I held it up for him to see, he back away like a vampire from holy water.  Ah, I now possess a behavior control talisman!

The City of Tulsa sign guys, myself included, take our job very seriously.  We are proud of our signs, and want them to look good and be correct.  If only other cities felt the same…

Tulsa’s New Numbering System

Wednesday, May 18th, 2011

Part of my duties as Tulsa’s sign guy is to identify signs that need to be replaced.  For the better part of the past year, I have been driving the neighborhoods identifying street name markers that need to be replaced, and given that Tulsa has upwards of 36,000 intersections, it is not a task that can be completed overnight.  I was in a south Tulsa neighborhood earlier today identifying such signs, when I drove past one that, while relatively new and in good shape, seemed a bit off.  I stopped, threw the car in reverse, looked at the sign again, and then was completely embarrassed.

Apparently, Tulsa has a number that no other place has – 93th.  Is that ninety-thith? Ninety-threeth?  Ninety-thrith?  And where exactly does this number fall on the number line – between 92nd and 93rd or between 93rd and 94th?

Not only is it embarrassing that a large and educated place like Tulsa could misidentify 93rd as 93th, it is even more embarrassing that no one ever noticed!  Obviously, the sign fabricator never noticed.  Nor did the sign installer.  And, given that this sign has been out on the street for several years, neither did any of the residents.

Needless to say, this sign has been added to my “REPLACE’ list!

When You Live In A City, You Don’t Always Get Your Preference

Wednesday, April 13th, 2011

I received an e-mail yesterday asking my professional opinion, as a traffic guy,  about San Francisco’s experimental market-based parking pricing program.

http://reason.org/news/show/san-francisco-parking-commentary

 For those of you who don’t want to go to the link, let me summarize-

San Francisco has determined that 1/3 of their traffic congestion is due to “circlers”, drivers circling the block looking for a parking place.  In order to reduce congestion, and reduce the number of double-parkers, San Francisco is experimenting with a system to vary the price of parking meters, with higher demand meters being more expensive, and lower demand meters being less expensive, in order to balance the parking load more evenly, with the ultimate objective being one free space on each block at all times.  Using high-tech meters and sensors, adjustments can, theoretically, be made real time.

This idea is not a new one.  Back in 2001, when Kevin, Ali, and I, did a comprehensive analysis of parking supply and demand on the campus of  Baylor University, one of our recommendations was a similar strategy, with high demand spaces being the most expensive and low demand spaces being the least expensive, with the overall objective being to balance out the parking demand evenly throughout the available parking facilities.

 Although I agree with the concept, I disagree with both the philosophy behind the reason for San Francisco’s program and the practicality of implementing it.  San Francisco’s objective is to always have one free space open on each block at all times to ensure that people have easy access to where they want to go.  This whole philosophy is wrong on several different fronts.  First, where does it say that any citizen is entitled to park wherever they want whenever they want?  Living in a city means that I, an individual, inconsequential  person, will be inconvenienced at times; if every single individual got their preference every time, the result would be gridlock, because inevitably my preference will conflict with your preference, and when that happens, whose preference wins?  Other that having a showdown at Big Sky and eliminating one of the conflicting parties, the only way to resolve the conflict is agreeing that neither of us can have our way; we both have to give a little.  Just a couple of hours ago, I was driving down a one lane one-way street when I met another vehicle driving the wrong way down the same street; it was a standoff.  Given that I could not go forward, and had vehicles behind me and could not go back, I parked my car and went to talk to the other driver, who was insistant that it was stupid that he should have to go around because he only wanted to go a few feet.  It was asinine, he told me, that he should have to be inconvenienced and preferred to drive the wrong way down the street.  Living in a city, however, we each do not always get our way, and he finally backed down, and me and the handful of vehicles behind me proceeded on our way.  If we go under the San Francisco logic that each citizen should have their preference, I’d still be stuck in the middle of a one-way street.  The whole concept that we can live in a larger group but always be able to get what we want, when we want it is lunacy.

The other part of San Francisco’s philosophy that we should be able to park in front of the business of our choice when we want is that it encourages laziness and obesity.  Walking a block or two is much better for the body then walking only a few feet.  Here we have the First Lady crusading against obesity and we have San Francisco saying that we will adapt our parking system to you so you don’t have to do any exercise, so you can get fat!  Of course, it may be a conspiracy to control population growth by making us all obese and croaking at an early age….

As for the practicality, when Ali, Kevin, and I made our suggestions for demand-based pricing on Baylor’s campus, we weren’t thinking that those prices would be dynamically adjusted for demand.  We were thinking that those prices would be set for say, a year, and during that year data would be collected to see how effective the pricing is, and make necessary adjustments annually.  No matter how much technology and sensors you have, you still have to have the personnel on hand to analyze the data, and it is not practical to have a person dedicated to only analyzing parking data 24/7 to make dynamic adjustments.  The new economic reality is that such one-task jobs are a thing of the past.  Furthermore, while technology is grand, it is also much more prone to malfunction.  Tulsa, for example, has replaced many of its old mechanical meters with electronic ones.  While the electronic gizmos have numerous bells and whistles, they are also a headache.  A dead battery, for example, renders them inoperable, and the electronics are much more susceptible to the extremes of the weather.

There is an easy solution to the double-parking and illegal parking issues.  It’s a big thing with wheels and flashing lights.  Yes, tickets do work, sometimes, depending on the willingness of the judge to let them stand.  A more effective device is a tow-truck.  Pay a couple of $100 plus towing and impound fees and you will think long and hard about double-parking.

Out With The Blah, In With The Cool

Thursday, March 10th, 2011

Tulsa has two freeways which are not on the state highway system which means, basically, they are city streets on steroids.  When I first came to Tulsa six plus years ago, neither of these two, the Gilcrease and the L.L. Tisdale, had freeway-type signage telling motorists what highway they were driving on.  Our then head signmaker, Frank, and I, spent the better part of a year testing different designs and color combinations for a sign that would be conspicuous, readable, and unique.  During the middle of this process, the Oklahoma Department of Transportation, in honor of the state centennial, changed the state highway route marker from a white circle to a white square with the shape of the state inscribed in it.  Having abandoned the circle, we adopted it for our freeways, with white lettering on a green background, and proceed to install our route markers on our two freeways.

Subsequently, the Gilcrease was extended two plus miles.  Since the city hired the state to manage the project, we were at the state’s mercy with respect to signage.  It is always dangerous to cede control to another entity, as you don’t have any control over the end product.  Instead of using our cool signage convention on the extension, the state used it own, a black-on-white square sign with hard-to-read-because-it’s-too-small text.  We received numerous complaints about the signage the state installed.   To add insult to injury, there wasn’t enough signage, so immediately after the opening of the freeway the city added a lot of signage, including several of our route markers.  Of course, that left a freeway with two very different looking route markers, but it didn’t seem wise to remove the brand new ugly state-installed ones and replace them immediately, as given what I know about Tulsa drivers, I was willing to gamble that they would be hit relatively quickly and we would have to replace them, anyway.  I was willing to wait a couple of years to save the taxpayers some money.

The Gilcrease was opened in December 2008.  It is now March 2011, and the remaining “ugly ducklings” along the freeway proper are no more, so they are being replaced with “beautiful swans”.  Okay, to a sign geek like me they are beautiful.

It has always been my philosophy that a knee-jerk reaction is the worst one, and that it is better to exercise some patience and wait, as time always seems to settle things.  By waiting a mere 27 months, we are getting our proper and consistent signage AND not having to pay for it twice, as we would if we had immediately changed signs.  In government time, 27 months is very short, like a blink of an eye.  Ah, if only I could convince others to have some patience and not jerk their knees….

It’s Not Easy Being Green

Thursday, October 7th, 2010
I was flabbergasted, surprised, and in a state of utter disbelief when we received a complaint about a green stop sign.  I take pride in my signs, and I was dismayed that somehow I could have missed an obvious flaw such as a green stop sign on my watch, in my city.
So, I did what every good traffic engineer would do – I immediately dropped everything to go an investigate a potential embarrassment.  To my dismay and horror, the citizen was right – there was, indeed, a green stop sign!
Yes, Virginia, it is GREEN!
Yes, Virginia, it is GREEN!

I was relieved to discover that it was not one of mine, but was on private property.  I happened to talk to the property manager, who said that that green stop sign had been there for six years, and then asked me a question for the ages -

“Stop signs aren’t supposed to be green?”
When I responded in the negative, he asked another question for the ages -
“What color are they supposed to be?”

A Weird Vindication

Tuesday, March 9th, 2010

A couple of years ago, I was contacted by a local motel owner who needed a structural engineer.  One of his buildings had been condemned, and he needed a structural engineer to evaluate it and make recommendations on how to fix the problems.

When I first saw the building, my first advice was that he should rip it down and start from scratch.  It was a two story, and the second floor deck was concrete and was in imminent danger of collapse.  Since the deck supported the roof, the roof was also in danger.  The wood columns holding up the balcony were old and rotted and warped, and couldn’t hold up the weight.  As the owner wanted to salvage the property, I came up with an appropriate design.

I replaced the concrete deck with a wooden one to lighten the load.  I also added additional columns between the existing ones for redundancy and strength.  Finally, I added a buttress directly from the ground to the roof and firewall so that if the structural integrity of the second floor happened to be compromised, the building would not fall. 

Along the way, the owner, in an attempt to save a few dollars, requested that I “tone down” the design, and I refused.  I repeatedly told him that as the engineer it falls on me if the structure falls, and I will not ever compromise safety to save a few pennies.  Having received my engineering education in Missouri, the lessons of the Hyatt Regency were pounded into my head (as well as the heads of every other structural engineer in the state).  My reluctance to budge might have been a bit prophetic, as the building caught fire Sunday night, thanks to a clandestine meth lab in one of the first floor rooms.

(Photo by TULSA WORLD)

(Photo by TULSA WORLD)

As you can see from the photo, my conservatism has been vindicated, as the structure is still standing.  Was the fire a disaster for my former client?  Absolutely.  Could it have been worse?  Absolutely?  Imagine what would have happened if he hadn’t hired an honest and ethical structural engineer, and shortcuts had been taken that compromised strength to save a few dollars.  Imagine the catastrophe if the building had collapsed with others still in it.

For twenty years, I have tried in vain to convince people that it is better to spend a few thousand dollars more to hire a professional structural engineer up front and do it right than to be cheap and not hire one.  The results of trying to save a few dollars could be fatal.

It’s Merely A Flesh Wound

Tuesday, February 23rd, 2010

     They reported in the local paper that a hazardous hole had formed on the I-44 bridge over 161st E Avenue, and that the lane had been closed because some cars had been damaged.

(Photo from the Tulsa World)

(Photo from the Tulsa World)

     I think that calling this a hole is as much of an understatement as The Black Knight calling the loss of a limb “merely a flesh wound.”  A hole?  Are you friggin’ kidding me?
     No, my friends, this is more than a mere hole.  This a what is commonly known as, “A big-*** chunk of the bridge is missing!”  You are not supposed to be able to wave at the traffic down below through a mere “hole”.
     What’s sad, is that this bad boy has a twin on the same bridge!  This, my friends, is bridge replacement, Oklahoma-style.  Yes, here in the Sooner State the bridges fall Sooner than later, because we don’t spend any money on maintenance.  You think I jest, but I do not.  Thanks the how the budgets are set up, you can have a bond issue and have hundreds of millions of dollars for replacement in a capital budget and not a penny for maintenance in an operation budget, and it against state law to transfer money from the capital budget to the operational budget.
     The solution to this dilemma?  Quite simple, actually.  Just don’t maintain anything, and sooner rather than later whatever it is that you’ve failed to maintain will fail and can be replaced with capital funds.  Neat how that works.
     And by the way, they are passing out hard-hats at the state for those passing through our great state so that you won’t get killed by falling bridge decks on your way to see the Sooners and their multimillion dollar coach, or the relocated Seattle SuperSonics that our legislature insisted on spending 30 million taxpayer dollars to lure to Oklahoma. 
     Yes, we do have our priorities right!

Why You Should Call Your Friendly Civil Engineer Before You Buy

Tuesday, January 26th, 2010

Wouldn’t it be a bummer if you plunk down $250000 for a house and it slides down a hill?

Soil Shift Evacuation

This is a real picture of $250000 houses in San Antonio sliding down a hill!  Of course, as always, the builder is being blamed for this mess by some very ticked off homeowners.  As with all of these types of cases, there will be lawsuits filed on behalf of the innocent homeowners against the evil, greedy home-builder who misled them into buying a house on a lot on the top of a bunch of fill.

What frustrates me about situations like this, and I’ve seen a bunch, is that the homeowner never ever accepts responsibility for his or her own stupidity.  Come on, who in their right mind would buy a house sitting on top of a bunch of fill being held in place by a huge wall?  Yes, there are walls that never fail, but more likely than not, they do fail because retaining walls tend to be built as cheaply as possible.  I speak from experience on this one, having designed 15 to 20 feet walls, only to have my designs spurned because they are “too expensive.”  Not to brag or anything, but good and responsible civil engineers like myself do design things that are built to last, only to be told “thanks, but no thanks.”  I once designed a foundation drainage systems for a homeowner that his contractor called “a Cadillac system”, only to have the homeowner opt against it to save a few dollars.  I’d guarantee that part of the reason that the retaining wall in the picture failed is because the foundation drains were inadequate, if they even existed at all.

Every seller and home-builder should require a home-buyer either get a letter from a registered civil engineer saying that the property has been inspected by an engineer and no deficiencies have been found OR sign an indemnity clause preventing them from suing the seller or builder if something like this happens.  Why should the seller be penalized because the buyer is cheap or lazy?  Remember – CAVEAT EMPTOR.