Thursday, March 23, 2017

The Leaning Tower of San Francisco

San Francisco, the land of leftist leaning ideology and now a leaning skyscraper.  The Millennium Tower, sarcastically referred to locally as the "Leaning Tower of San Francisco" opened in 2009 but by November 2016 had settled up to 16 inches (based on publicly available reporting) and tilted 2 to 6 inches apparently to the northwest.  New settlement appears to continue, one reference indicating 1 to 2 inches per year.



The building was constructed (apparently) on skin friction piles through an old landfill and presumably into local native soils above bedrock (but not bearing deep to reach bedrock).  The geotechnical report by Treadwell and Rollo (firm acquired and is now a part of Langan Geotechnical) could not be obtained, but obviously there was a geotechnical modeling error that seriously overestimated skin friction capacity or underestimated any negative impacts from pile group settlement, or maybe the structural engineer underestimated dynamic structural loads (i.e. storm wind loading) given to the geotechnical engineer that would be maximum loads on the piles on one side of the building, i am only speculating.
Crack monitors are seen here on a lower level concrete wall.  Distress was also visible in the exterior sidewalks and their joints to the building.








You can research online all the litigation and municipal public policy issues that have arisen due to this fiasco, if you are curious to learn more about this situation.

If you are a Geotechnical Engineer working on a high rise project with recommended foundations supported on soil and not rock, you must, must, seek secondary review and commentary from another Geotechnical Engineer (or two), these projects are too expensive and too exposed publicly to permit any errors.  And in California where earthquakes occur, one has to wonder how this building will perform with piles embedded in saturated soils beyond a certain depth, soils susceptible to liquefaction.  Earthquake engineering is not a part of my purview of expertise so i defer to the California Geotechnical Engineers to figure this one out.

Saturday, August 20, 2016

How often do water supply lines or sanitary sewer lines leak?

As reported by the Austin American Statesman, during the hot drought period in 2011 in Austin, the Austin Water Utility via spokesman Jason Hill reported 55 calls a week average concerning broken (leaking) water lines.  The typical average during summer seasons is 35 to 40.  "A good portion of the ones we are seeing are the small lines from the water mains to the homes."  In 2009 40 to 60 leaks a week were reported in June, July, and August, with a peak of 66 in the last week of August.  In 20111 a high of 103 leaks was reported in the last week of July.  Another figure reported for 2011 was 60 to 80 per week.  October 2011 reported approximately 50 leaks per week.

Texas municipalities reported system leak rates in 2013 and the leak rate varied from 4% system wide loss to as high as almost 18%.  Water mains under residential streets can impact house foundations in the adjacent lots.  Leaks in the feeder lines to homes also contribute to the loss.

Back in the early 21st century when many geotechnical engineers were assisting insurance companies with homeowner's insurance policy claims related to house damage with a suspected cause being soil movement and plumbing leaks, hundreds and hundreds of claims were apparent.  Many of these claims did reveal plumbing leaks.

It is foolish to design site preparation and foundations based on the assumption that either (1) a plumbing leak will not occur, or (2) if a plumbing leak occurs well then the owner is out of luck.  This is ridiculous.  You do not design building foundations based on luck, particularly for a condition with a relatively high probability of occurrence.








Subdivision in Hutto Falls Apart Due to Expansive Clay

Andrea Lorenz reported on this case for the Austin-American-Stateman back in 2008:

"The soil that made the town of Hutto a destination for farmers in the 1800s has caused headaches for some of the area's 15,000 or so new suburbanites.

  Homeowners in at least two subdivisions are facing problems so extensive that the builder moved some residents out of their homes for weeks while repairs were made.

City officials say the problems, which might affect all 787 homes in the Hutto Parke neighborhood and several homes in Legends of Hutto, are not serious structural issues. But they have spurred the City Council to consider a more stringent building code.

Some residents say problems are structural, caused by inadequate foundations for the type of soil in Hutto. They say their homes have not been repaired, and they have taken their grievances to the Internet, looking for others in similar straits.

At issue is the black clay that gives the Blackland Prairie region its name. The soil requires extra precautions by builders or homes will shift more than usual. The clay expands and contracts with moisture. If foundations are not designed to handle that movement, the stress can cause cracks, popped nails and separation between walls and ceiling trusses.

Marion Wallace had problems with the house she bought in the Hutto Parke subdivision in 2004. Like most of her neighbors, she agreed to let the builder, Lennar, remedy the problems, which included prefabricated roof trusses attached too tightly to the walls.

"It was the most stressful, harrowing ordeal that I've gone through," Wallace said. "They take your whole house apart and put it back together again."
Last year, the city first heard from homeowners about problems in Hutto Parke and the Lennar-built homes in Legends of Hutto, according to the city's former chief building inspector, Dan McDowell.

The problem stemmed from the nails attaching the roofs to the drywall being too close together, so there was not enough give for the foundation to move without cracking the drywall, according to Kathy Kirtz, Lennar's regional director of customer care.

Kirtz would not say how many homes are affected, but she said the company sent letters to residents of two subdivisions in Hutto explaining the situation.
Kirtz blamed the problems on subcontractors hired by Lennar, but she did not name them.

To fix the homes, workers were reinstalling the drywall, Kirtz said, but after the repairs started last year, the workers discovered a less invasive process. They now make the repairs through the attic, she said, so the residents don't have to move out.

She acknowledged the soil is part of the problem but said the ultimate cause was too little space between the nails attaching the roof to the drywall. "Match that with foundations moving as they should, and that was causing the cracking in the ceiling lines," Kirtz said.

Some homeowners and housing advocates say the repairs aren't enough. One resident, Mike Crump, started a Web site, www.searchhutto.com, where homeowners share horror stories.

Charles Fain, 44, operates a page on YouTube where he posts videos of interviews with Hutto Parke residents and homes still under construction. A former schoolteacher who now works in customer relations at Dell, Fain bought his home in 2004 after seeing a sign for zero down payment on a new home. He has put about $17,000 into his home, he said. The appraisal district last valued the home at $103,000; Fain paid $119,000. He's not sure if it has decreased in value because of what has happened in the neighborhood.

Lennar's Web site prices new homes in Hutto Parke from $137,490 to $161,490.
Fain decided to run for the Hutto City Council in May because he said some members of the council weren't responsive to the Hutto Parke residents' problems. He's running against McDowell, who retired from his staff job to seek a council seat.

City staff members hope the city's new codes, to be developed with public input and council discussion in the next year, will prevent problems. But critics say the city and home builders are being dismissive of the more serious concerns.

Janet Ahmad, president of the San Antonio-based Homeowners for Better Building, said her organization has heard complaints statewide the past three or four years about nails popping out of walls. She said the ones in Hutto Parke are caused by problems in the foundation and extra wall movement, based on her experience working with homeowners.

She says home builders in Texas should be held to stricter codes. In areas with expansive soil, builders should bring in more stable soil on which to put foundations, grade the front and back lawns, and take other measures to make sure foundations are secure.

The dirt below Hutto expands more than that of the rocky land west of Austin, said Mike Risinger, a soil scientist with the state.
The Hutto soil shrinks when dry and swells when wet. If a portion of land below one side of a home gets wet but the other side is dry, Risinger said, the house will shift, and foundation slabs can crack.

The U.S. Department of Agriculture Natural Resources Conservation Service has determined that most of the land in Hutto is made up of the most expansive type of clay. According to the department, the soil is "very limited" for building, with weaknesses that "generally cannot be overcome without major soil reclamation, special design, or expensive installation procedures." The agency recommends several precautions during construction to counteract the soil's weaknesses.

Building plans submitted to the city for Hutto Parke homes stipulated that the foundations be constructed for clay soil with a high movement rate and included instructions such as replacing the clay with a more sturdy filler. Both Lennar and the city said the homes were built according to those plans.
The area around Manor has similar soil, according to soil scientists. The city hasn't had problems with new homes, said development director Tom Bolt. However, the foundations of many homes built in the 1930s and 1940s have had to be replaced.

In Hutto, Fain has been meeting with elected officials to get more help. For most disgruntled homeowners, the process involves filing a complaint or requesting an outside inspection through the Texas Residential Construction Commission.
Twenty-one people in Hutto have complained to the commission in the past three years. Of those, eight complaints were about Lennar Homes, and all eight cases have been resolved or closed.

About 40 Hutto homeowners have hired a law firm in Austin to help them resolve their problems.

Attorneys Amy Welborn and Richard Alexander say no lawsuit has been filed and wouldn't say whether one would be, but they said some things were not revealed to their clients when they purchased their homes.

Several homeowners used government-backed loans to purchase their homes, and in the applications, Lennar indicated the homes were not built on expansive soil, even though the city says they were. Kirtz said marking the wrong box on the loan application was a clerical error.

The federal government investigated five claims in Hutto Parke after prompting by U.S. Rep. John Carter, R-Round Rock, said Patricia A. Campbell, a spokeswoman for the U.S. Department of Housing and Urban Development.
Officials at the Denver Homeownership Center, a HUD agency, concluded that under the home warranties, Lennar is obligated to take care of any defects in two of the homes. In those cases, the government won't be doing anything further, Campbell said in an e-mail.

Two other cases are still under review. One case was dropped.

Eagle Ford Clay Wrecks House in Mansfield

Amid thousands of homes in Texas that suffer damage from expansive clay soils and arguably improper structural and geotechnical design or Builders taking chances, this is just one case history that made it to the Texas Supreme Court.  The following is by Wayne Slater of The Dallas Morning News (2007)....The house was constructed on what appears to be the "Eagle Ford" geologic formation, which frequently contains expansive clay.  The Builder was Perry Homes, who similar to almost every other spec home subdivision builder, resists the expense associated with proper site preparation and foundation design techniques to build homes.

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"In the beginning, Bob and Jane Cull thought if they just wrote homebuilder Bob Perry a letter about all the defects in their new Mansfield house, everything could be resolved.

A tortuous legal battle has carried the retirement-age couple through the courts, to arbitration and now through the courts again — all the way to the Texas Supreme Court. The Culls have won every round, but their home has not been fixed, legal costs have soared and the couple has postponed retirement plans.

"You think you can wake up from a nightmare and it'll be over," said Jane Cull, a physicians' liaison. Instead, the couple watches as the home's defective foundation continues to move, some windows won't open and more cracks form in walls, according to engineering reports.

A spokesman for Perry said the case is built around an important principle: whether arbitration or the courts will settle disputes. But the Culls say their case against Perry Homes illustrates how construction disputes can last for years without resolution and how the system is stacked against average homeowners who challenge homebuilders with wealth and political influence.

Particularly this builder: Perry is the nation's most generous individual political donor. He has been a leading advocate of laws to limit court awards against businesses and a financial benefactor to politicians and judges. And he has funded Republican candidates up and down the ballot in Texas, including more than $340,000 to the nine justices that will hear the Culls' case.

Perry Homes spokesman Anthony Holm said the donations are irrelevant.

"All we're trying to do is get our day in court," Holm said.

The Culls filed suit in 2000 to force repair of their house. But they grew concerned a legal battle could take years and went to arbitration instead, thinking it would resolve the issues quicker and with less expense.

Holm said the switch was unfair to Perry Homes, which had spent time and money preparing for a trial. He says the couple waived its right to arbitration.

It is that legal question — "at what point in time does a consumer waive their right to arbitration?" — the high court has been asked to decide, he said. Arguments will be heard in March.

Consumer advocates say Perry has spent millions of dollars creating a political and legal system tilted in his favor.

"It's not surprising that he showered tens of thousands of campaign dollars on the Texas Supreme Court," said Andrew Wheat of Texans for Public Justice, a nonprofit group that tracks campaign contributions.

"What is shocking is that the judges who took all this money have agreed to hear Perry's appeal of a lemon-home case — one that he already lost in front of an arbitrator and two Texas courts," he said. "It's three strikes and you're out in the Texas justice system — unless you own the league."

Wheat's group receives financial contributions from trial lawyers that represent people suing businesses.

Bob Cull is 69, a stout man with round spectacles and suspenders who works as a manager in the health care industry. His wife is 64, petite with white hair, and she carries a briefcase stuffed with documents about the couple's legal odyssey.

When they signed on with Perry Homes in 1996, the Culls thought they were building their dream retirement home, with 2,800 square feet and upgrades such as cedar closets and raised arches, in a new subdivision south of Fort Worth. There was a golf course and a view of the pond.

"I can remember sitting on the property before there was a house on it, watching the sunrise, and thinking, 'Oh my, this is the place,'" Jane Cull said.

"This was going to be our forever, On Golden Pond nest," she added.

But the house was never whole.

"First we thought they'd bought the wrong-sized door," Jane Cull said. "Leaves and critters could come in. Roof supporters were not staying attached in the attic; they were just hanging free. And there were cracks in the walls and the tile was cracking."

The couple complained, but work crews simply patched the problems, they said. Soon, they were sure their new $250,000 home had fundamental defects, and they expected Perry to make it right.

Bob Cull described himself as "a firm believer that people settle their differences face-to-face and resolve things on a kind of man-to-man basis. We thought this was something we could talk to Bob Perry about over a cup of coffee and settle with a handshake."

He wrote to Perry, the first of many letters to come, outlining the problems. Engineering reports, both by the Culls and by the warranty company contracted by Perry Homes, concluded the foundation was defective, he said.

Their house was now valued at perhaps only a third of the original purchase price.

Eventually, the couple got a letter from the attorney for Perry Homes, John Krugh, saying the firm had done all it was going to do. Perry Homes had provided surface drains, patched the walls and sealed gaps in the concrete, but made it clear it bore no more responsibility for the Culls' problems.

In October 2000, the Culls filed suit against Perry Homes. But before the case went to trial, the couple had second thoughts and moved to have the matter decided by an independent arbiter because, now in their 60s, they feared spending their retirement years in a long legal battle.

The homebuilder resisted and both sides went to court. A district judge, the appeals court and the Texas Supreme Court all ruled for the Culls and directed that both sides go to arbitration.

After several days of hearings in 2002, an arbitrator directed Perry Homes to pay the Culls more than $800,000. That includes the cost of the house, punitive damages and legal costs. With interest, the award would now top $1.3 million.

In a lawsuit, discovery rules govern how the two sides must share information. The Culls' attorney says the couple got nothing in discovery it couldn't have gotten in arbitration, but Holm says the Culls got information the company didn't, and that the arbitrator was biased against the homebuilder.

"There appears from our perspective to have been very real bias on behalf of the arbitrator," said Holm. "And there is a real question about when the plaintiff waived their right to arbitration."

A district court rejected those arguments. Perry Homes took the case to the appeals court, which also ruled for the Culls. The homebuilder again appealed to the Texas Supreme Court, which has scheduled a hearing for March.

The attorney for the Culls said he was surprised the high court, which accepts a fraction of the appeals it gets, agreed to take the case.

"I'm certainly concerned there's politics at play," said Dallas attorney Van Shaw. "The law's clear. We're entitled to win and lots of courts have seen it that way. So I can't reach any other conclusion than it's politics."

Holm denied that. He said public disclosure of Perry's contributions to all nine judges makes his legal burden more difficult "because every justice there knows there's some kind of donor relationship."

"I have faith in all the justices and ... the justice system in Texas that things are being decided on the merits," he said.

The court does not explain its reasoning for accepting a case.

[...]

But the toll on them is mounting, and they hope the dispute is nearly over. A favorable ruling would end the matter. But if the high court vacates the arbitration award, it would send the case back to district court for litigation that could take several more years.

In the meantime, Jane Cull said recently, "We can't fix our house. We can't sell our house. The warranty company can't fix or sell the house."

They've kept up the appearance of the home, patching and painting. Some windows won't open. Some doors have to be jerry-rigged to close. Cull worries about how any future shifting might affect gas pipes and electric lines.

"These are the rooms where your grandbabies are taking a nap," she said.

Financially, the couple can't move. Bob Cull, who had planned to be retired by now and faces some health issues, has gone back to work managing a small pharmaceutical business in Arlington. Jane Cull continues to work as a liaison for a physicians' group.

"I'm no legal eagle. I'm just a mother and a grandmother and homeowner who would like to have some freedom from stress and fear over where I'm going to live the rest of my life," said Jane Cull. "When you're in the final phase of your life, that's pretty frightening."

She shrugged. "We're kind of like in homeowner purgatory. And we've been here for 10 years."

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The Texas Supreme Court sent the case back to District Court.  In 2010 a jury ordered Perry Homes to pay the Culls $51,000,000 (sounds a little bit outrageous).  $7 million was for damages and $41 million was punitive (ouch).  

Abandoned Construction Project due to Sloping Del Rio Clay




Now called the Hope Outdoor Art Gallery, where graffiti "artists" can practice their talents, this site with abandoned concrete slabs and concrete walls and unknown foundation elements was abandoned back in 1985.  This site on Baylor Street in downtown Austin was intended to be office space for high-tech industry professionals.  Instead foundation problems occurred during construction and a dispute between the Developer (Owner) and the General Contractor shut the project down.  The building permit expired in 1987.  The site was purchased by a bank in 1989.  Some demolition of superstructure elements occurred but the at-grade and below-grade elements remain.  This site lies downslope of the "Castle Hill" building (former Texas Military Institute site).  A lawsuit by the Developer was settled out of court and included the Geotechnical Engineer and his firm, Trinity Engineering and Testing Corp (now Kleinfelder) and all other parties on the project team.



Slopes on expansive clay formations are inherently unstable.  I suspect downward slope creep occurred as the project team cut and fill along the slope and applied new surcharge loads.  I do not have any information on the foundation design or as-built foundation data.  The lesson learned is that you develop sloping sites on massive clay soil with extreme caution.











Saturday, August 6, 2016

Do not forget the flatwork





In 2012, less than 2 years after ACC (Austin Community College) opened the new campus in Round Rock, Texas, school officials had to budget $2,000,000 to make repairs associated with expansive clay soils.  Fortunately, most of the problems had to do with the flatwork and not the building.  Too often geotechnical engineers focus attention to the buildings (in this case structurally supported slabs cast on void boxes and constructed on concrete drilled piers) but not enough attention to pavement and flatwork in expansive clay soil environments.

Geotechnical work had been performed by Raba Kistner and architectural detailing by GSC Architects.  Uncertain who were the Structural Engineer and Civil Engineer.

One media source reported that some type of soil improvement was attempted in the flatwork areas (6 feet deep of lime injection possibly?).  However, flatwork (sidewalks) had heaved so severely in some areas that doors could not be opened or closed properly.  Good quality geotechnical reports will address the concern with a structurally supported building slab abutting exterior flatwork.  Sidewalks had to be closed due to tripping hazards.

In 2015 ACC reported that soil movement resulted in surface water (rainwater) entering Building #3000 during heavy rain events.  Heaving and shrinking clay soils will change surface drainage profiles, and both the Geotechnical Engineer and Civil Engineer are responsible for addressing this concern with property owners or developers.

Construction repair bids included one $434,000 proposal to install surface drainage swales, install pedestrian grates over the swale, resurfacing of building flatwork to correct drainage issues, and installation of new stormwater drain along one face of Bldg. 3000.

A photo of sidewalk reconstruction efforts is below.  When you consider the $2,000,000 budget for flatwork and drainage repair, I cannot stress enough how important geotechnical, structural detailing, and civil engineering plan detailing are with regards to flatwork and pavement in expansive clay soil environments.  It starts with the Geotechnical Engineer properly informing the project team of the risks and concerns, and the Civil Engineer and Structural Engineer to formalize final design details.


The purpose of this post is to warn fellow Geotechnical Engineers and Civil Engineers (site grading and drainage) to pay more attention to detail on expansive clay soil environments.  The geotechnical study for this site was probably on the order of $20,000, but omissions of recommendations for dealing with flatwork abutting buildings cost the client $2,000,000 for a $114,000,000 facility.  Ouch.


Saturday, June 1, 2013

COE sues Architectural-Engineering firm for expansive clay damage to utilities

[This case was described in Civil Engineering Magazine in 2013, article written by Michael C. Loulakis.  I have condensed it.]

BPLW Architects and Engineers, Inc. provided the MEP design for two student dorm bldgs at Lackland Air Force Base in San Antonio.  Soon after construction was completed, water leaks occurred that even flooded several rooms.  The US Army Corps of Engineers (COE) repaired the broken pipes and replaced the sanitary sewer pipe system.  The COE billed the MEP firm $7,600,000 for the damages and repair work (negligence or omission claim against the MEP firm).  BPLW appealed to the US Court of Federal Claims.  Heaving clay soils and poor surface drainage design were suspected of having led to the pipe damage and flooding damage.

The "standard of care" requires that the MEP firm consider the geotechnical report ("soils report") when designing underground utilities.  The geotechnical report actually warned that the clay soils at this site could heave 9 inches (i.e. worst case scenario).  The construction contract documents, however, included a mechanical connections section and the MEP firm did abide by the requirements of that section, which apparently included language about tolerating 1 inch of differential movement at horizontal to vertical transitions and possibly 4 inches as the horizontal moves away from a vertical run.  The MEP firm was also accused of producing poor drainage plans (grading and drainage).

The Court determined that the MEP firm's design, as well as its grading plans, failed to comply with the contract and the applicable "standard of care".  But there was also testimony that the GC did not install some of the piping system correctly and that the GC had installed a bent and broken piping component under the slab.  There was uncertainty as to whether the GC had graded the site properly for drainage design (no as-built data).

The Court determined that the COE FAILED TO PROVE CAUSATION.  i.e. the COE did not demonstrate that the design, in contrast to other factors, caused the damage directly.  The COE also did not show that the negligent surface drainage design led to the improper grading and ponding of water.  Poor pipe installation by the GC was the potential intervening cause of damage that allowed the MEP firm to escape this claim.

In addition to failing to prove causation, the COE was also determined by the court to have failed in proving a reasonable damage assessment.  The COE witnesses were not experts and provided insufficient testimony on whether the scope of repair work was reasonable or necessary.  i.e. was that $7,600,000 work all necessary and was that cost reasonable.

The court awarded the COE a small amount of $ for certain modifications it had to make to the MEP's design, but most of the other money was not awarded.  As the prevailing party, the MEP was able to recover money from the COE for legal costs, to make matters worse for the COE.

Lesson learned for geotechs: In cases of negligence claims, the Owner or other suing party has to PROVE CAUSATION.  Even if found having breached the "standard of care", the engineering firm's error has to also be found to have actually directly caused the damage and losses.  If the engineering firm can show that construction errors could have caused soil movement or damage, then causation cannot be linked directly to the design.  Now if the GC performed their duties correctly and installed everything per plans and specs, then your error may indeed be the cause and you simply just need to have your insurance company handle the claim.  Another lesson: geotech should address buried utility construction.  I dont know what was in the geotech report for this site but i am surprised the COE did not sue them for omissions (i.e. lack of recs addressing buried utility construction and connections).  Some will argue the opposite: the less you say, the better.