Thursday, July 30, 2020

Three Gorges Dam showing severe instability?


This report was put up by the Florida Marquis.  He specializes in using Google Earth and uses all the advanced tools available.  What he shows is huge structural deformation in the top of the dam itself well beyond anyone's comfort levels.  Do look at it. I cannot vouch for him.

What this tells me is that the foundations have been transitioning through high pressure water injection into an effective fluidized bed.  This dam cannot operate anywhere near flood levels at all and if we are allowed to do so, it must be draind to a safe loading level that allows such a flood to arrive.

If the dam fails over the next few weeks, expect to see a partial collpse and a possible breach which could easily chain saw the dam in half.  This is still a slow process that allows an uncontroled lowering of the resovoir.

All this is survivable.  This is the biggest dam of its kind and pushed what i would describe as theoretical failure modualties.  It is a mile long which is not a problem by itself.  however it is also 181 metres high.  That is a lot of pressure into the underlying rock which is known to be weak  Real rotation of the Dam cross section must surely weaken that foundation and allow deeper water penetration.

The images shown are profoudly trou.bling.  

.

three Gorges Dam.





China massive flood update: Three Gorges Dam ‘leaked, moved and distorted but safe’

08:58 | 22/07/2020Jasmine Le

Beijing has admitted in a rare revelation that ts 2.4-kilometer Three Gorges Dam spanning the Yangtze River in Hubei province “deformed slightly”, with some nonstructural, peripheral parts of the dam had buckled, after record flooding. 



According to China Three Gorges Corporatoin, the dam’s deformation occurred last Saturday when flood from western provinces including Sichuan and Chongqing along the upper reaches of the Yangtze River peaked at a record-setting 61,000 cubic meters per second.

“The dam had ‘deformed slightly,’ displacing some external structures, and seepage into the main outlet walls had also been reported throughout the 18 hours on Saturday and Sunday when water was discharged though its outlets”, the corporation notes. 

But the problem of water seeping out did not last long, as the dam reportedly deployed floodgates to hold as much water as possible in its 39.3 billion-cubic-meter reservoir to shield the cities downstream from the biggest Yangtze deluge so far this year.


A report cited by Xinhua stressed that all metrics were still up to standard and all the variables being monitored fell within the design parameters.

Three Gorges Dam, the world’s largest hydroelectric gravity dam was a pet project of the late Premier Li Peng and a monumental pride of the nation when it blocked and diverted Asia’s largest river in 1997, as reported by Asia Times.

China is in another all-out mobilization following the Covid-19 plague as virtually all southern provinces have been drenched by rainstorms unseen in decades, with many rivers overflowing within the dam’s catchment area.




The Three Gorges Dam on the Yangtze River in Yichang, Hubei province (Photo: Reuters) 

China said the deformation of the Three Gorges Dam ‘rumour’ shows lack of basic knowledge

Chinese engineers and mechanics experts on Tuesday denounced the reports, saying the reports were taken out of context and exposed their anti-China mindset and lack of basic physics knowledge, Global Times said.

Accordingly, the engineers noted all objects subjected to force, including dams, roads and bridges, will display displacement and deformation to a certain extent. The elastic deformation is recoverable and not permanent, and that of the Three Gorges Dam has always been within the design limits.

The deformation smear also emerged in the summer of 2019 when the dam was holding floodwaters during China's rainy season. Chinese experts explained at the time that the dam was not on the edge of collapsing, and only had elastic deformation within the designed limits of about 1.4 to 26.7 millimeters. 

Another slander in July 2019 cited satellite images of Google Maps showing the Three Gorges Dam "seriously distorted." Though the "distortion" later proved to be caused by low resolution of the image, the "deformation and collapse prediction" continued to circulate.

Zhang Shuguang, chief engineer of China Three Gorges Corp (CTG) noted that the dam has a monitor system with more than 12,000 detection spots, which will sound an alarm if there is a minor abnormality. The lifespan of the Three Gorges Dam is said to be beyond 100 years.

Real-time monitoring data shows that buildings and foundation of the Three Gorges Dam are working in a normal, safe and reliable manner, said the company. "Speculation without scientific monitoring data is irresponsible and unprofessional, or out of ulterior motives!"


Floodwater discharged from the main outlet of the Three Gorges Dam (Photo: Xinhua) 

High flood levels ravage the world’s largest hydroelectric facility

Final week, a number of days of contemporary rain introduced the water stage on the dam, positioned a number of hundred miles upstream from Wuhan in central Hubei province, to its highest level since development was accomplished in 2009.

The water stage within the reservoir was greater than 50 toes greater than its flood-limit stage, with inflows reaching 61 million liters a second through the peak of the rainfall on Saturday, China’s state-run Xinhua Information Company reported. The enormous dam is able to dealing with inflows of about 83.7 million liters a second.

China’s meteorological authorities anticipate heavy rainfall to proceed to pound the Yangtze River basin within the coming days, bringing extra flooding to the realm.

Chinese language chief Xi Jinping, talking final week, described the flood-prevention state of affairs as “grim” and having “entered a vital interval”.

The newest spherical of flooding compelled jap Anhui province to open up two dikes and blast one other two to launch waters, inundating some 45,000 acres of arable land. The province on Saturday raised its flood alert to the best stage.

Extreme flooding in Chongqing, a metropolis of some 30 million folks that’s upstream from the dam, and in cities in Hubei province which can be downstream from the dam, has shut down enterprise and site visitors and disrupted the lives of residents.



The flood has disrupted people's life (Photo: New York Times) 


In Jiangxi province, Li Qian’s household has been trapped on the highest ground of their two-story home for greater than per week since rising waters from Poyang Lake, China’s largest freshwater lake, swamped his village. Mr. Li and younger males from different close by households have teamed up to herald groceries and different requirements on small boats.

Torrential rain also caused three landslides on Thursday in a town in the mountainous municipality of Chongqing, upstream on the Yangtze, leaving six dead, the Chongqing Emergency Management Bureau said. The bodies had been found by Friday evening after more than 200 people were dispatched for search and rescue. The rainfall in the town of Dunhao totalled 39cm (15 inches), according to SCMP.

No comments:

Post a Comment