When a shoring system fails, lives are put in danger, the stability of neighboring ground can be compromised, projects are delayed, and often significant sums of money must be spent to correct the mistakes. From small projects to large projects the upmost care must be taken in every part of a shoring wall's engineering and construction.

When these risks are ignored, due to poor workmanship or lax standards, spectacular failures can occur. Here are some projects untaken by other companies that illustrate the danger that an improperly constructed shoring or foundation system can pose.

Crane Collapse

ctvtoronto.ca

It was a close call for construction workers in Thornhill after a crane collapsed at a condominium site.

Emergency crews rushed to the north east corner of Dufferin Street and Steeles Avenue at about 8:30 a.m. after a passerby witnessed the crane crash and called police. The operator of the crane was slightly injured and was treated at the scene by paramedics.

He was still inside the operator's cab, which was leaning against the side of the six-storey building. Paramedics used a crane to to extract him using a basket.

"The operator was swinging around to the west, at which point, our report is he heard a series of large snaps," said Sgt. Patrick Anderson of the York Regional Police. "The back part of the crane let go, and fell into the inside horseshoe portion of the building. The large extension of the crane fell on the opposite building, came over top and landed near the sidewalk area of Dufferin Street."

One worker on the site said saw the crane waving in the air, so he ran beside a forklift for protection. Another said the ending to the accident could have been a lot worse.

The crane toppled onto a building that was under construction, said said York Regional Police Const. Gary Phillips. However, all workers were accounted for and no one suffered serious injuries. Workers are building a new retirement home. The site already has two finished condominiums. Phillips said he's not sure what caused the crane to collapse. The Ministry of Labour will be investigating the incident.

CTV Toronto's John Musselman said the operator told investigators it felt like the whole accident happened in slow motion. He became injured when debris scraped off the building broke through the cab's windshield and hit him in the head.

A second crane was to be brought in to help clean up the scene, Musselman said.

With a report from CTV Toronto's John Musselman

Building Collapse

Shanghai, China

At around 5:30am on June 27, an unoccupied building still under construction at Lianhuanan Road in the Minhang district of Shanghai city toppled over. One worker was killed. According to information, a 70 meter section of the flood prevention wall in nearby Dianpu River and that may have something to do with this building collapse.

(1) An underground garage was being dug on the south side, to a depth of 4.6 meters
(2) The excavated dirt was being piled up on the north side, to a height of 10 meters
(3) The building experienced uneven lateral pressure from south and north
(4) This resulted in a lateral pressure of 3,000 tonnes, which was greater than why the pilings could tolerate. Thus the building toppled over in the southerly direction.

The plan called for an underground garage to be dug out. The excavated soil was piled up on the other side of the building.

Heavy rains resulted in water seeping into the ground.

The building began to shift and the concrete pilings were snapped due to the uneven lateral pressures.

The building began to tilt.

Collapse.

(China Daily)

Improper construction methods are believed to be the reason of last Saturday's building collapse in Shanghai, according to a report from the investigation team. The investigation team's report said that workers dug an underground garage on one side of the building while on the other side earth was heaped up to 10 meters high, which was apparently an error in construction, according to a report on eastday.com, Shanghai's official news website. "Any construction company with common sense would not make such a mistake," said an expert from the investigation team.

Earlier this week, there were also reports saying that cracks on the flood-prevention wall near the building, as well as the special geological condition in the water bank area, may be part of the reason for the collapse. "These factors are not the basic reason of this accident," said the expert.

Nine people linked to the building collapse, including the real estate developer, contractor and the supervisor for the project, have been put "under appropriate control", said the official Xinhua News Agency Sunday evening.

(SCMP) Firm's ignorance led to toppling of Shanghai building, report says By Will Clem and Lillian Zhang. July 4, 2009.

An official investigation into the collapse of an unfinished building in Shanghai has said that the accident was due to the construction company's "ignorance", rather than flaws in the design or building materials. However, the report stopped short of apportioning blame, and has been criticised for failing to address key issues.

The report said the collapse was caused by earth, excavated to make a 4.6-metre deep pit for an underground car park alongside the building, being piled to depths of up to 10 metres on the other side of the structure. The weight of the pile created a "pressure differential" which led to a shift in the soil structure, eventually weakening the foundations and causing them to fail. This situation "may" have been aggravated by several days of heavy rain leading up to the collapse, but investigators would not say whether this was a crucial factor. The report said the construction company - Shanghai Zhongxin Construction - "did not consider clearly" that the earth pile could have such a devastating effect.

Investigators stopped short of saying whether the company's errors were negligent or easily avoidable. However, they stressed that the building's foundations and construction materials all complied with the city's building regulations.

Huang Rong , director of the Shanghai Urban Construction and Communications Council, said inspections had shown that none of the remaining 10 apartment blocks was in immediate danger. "The surrounding buildings are now stable," he said. "The safety inspection of these homes will be the second phase of our professional team's work."

Jiang Huancheng , an architect and a lead investigator for the report, said it had been an "enormous shock" to see the site for the first time. "In my 46 years in the industry, I have never seen or heard of this," he said. "To put it simply this was ignorance leading to rashness. We need to take this accident as an important lesson ... and ensure that it does not happen again."

Several days before the release of the report, Wu Hang , Mr Jiang's assistant, accused the construction company of incompetence and lacking "common sense". Mr Wu said the investigation had found there had been no structures to support the walls of the car park pit, and this had been a key factor contributing to the accident.

Infinity Tower Shoring Collapse

Dubai, United Arab Emirates

According to this article published by Gulfnews.com:

Nearly 100 workers at the site of the 'tallest building with a twist' had a lucky escape yesterday as a wall holding back the Dubai Marina waters breached and flooded the foundation site. Excavation work on the 80-floor Infinity Tower was nearing completion when there was a sharp and loud sound, said a worker. "We then saw sand pouring down the sides," he said. The workers were ordered to evacuate immediately, said the foreman. The Dh700 million 80-floor tower is to have a 90 degrees twist. According to a manager of Arabtec, the incident is under investigation.

Here are some photographs of the resulting chaos caused by the failure of the site's shoring wall.

This is why Geotechnical reports are vital for crane lifts