Social News
Written by: Huang Weilun
2020-01-03 22:54
Last updated: 2020-01-03 22:55The Sand Central hearing was resumed on the 3rd of this afternoon, and was provided by Liu Zhihong, an independent structural engineering expert appointed by the government. He said that the steel bar must be butt to butt 末端 at the end, otherwise there will be looseness affecting the concrete and durability, emphasizing that the project should not be limited to safety only at this moment, but it will be durable and safe in the next 120 years.
Liu Zhihong also refuted the independent expert appointed by Leighton, who believed that the reinforcement project would not damage the original steel bars, and believed that his statement was impossible.
Liu Zhihong, an independent structural engineering expert commissioned by the government, stated that the steel bars must be butt to butt 末端 at the end, otherwise there will be loosening and affect the stone puddle. Stronger projects should not be limited to safety at this moment, but be durable and safe in the next 120 years. (Photo by Huang Weilun)
Earlier hearing revealed that in addition to Liu Zhihong, the other three independent experts appointed by Leighton, MTR, and the Commission of Inquiry all believed that the steel bars do not need to be docked. Among them, at least Leighton and the Commission ’s experts also believe that the reinforcement project may affect Structural safety.
Liu Zhihong repeatedly stated in court today that the steel bars need to be connected at the ends, and emphasized that Hong Kong's past tunnel projects must be connected at the ends. He described that if it was not properly connected, it might loosen and deform, and even cracks in the nearby stone puddle would affect durability.
Liu Zhihong also said that if the Hung Hom Station project is to be safe and its original purpose, it is not only safe at the moment, but it will remain safe for the next 120 years, and it is about durability.
According to Nick Southward, an independent structural engineering expert appointed by Leighton, the reinforcement works were first cut and drilled. There was a high risk of damage to the steel bars underneath. (Photo by Huang Weilun)
At the end of 2018, MTR started a comprehensive strategic evaluation of the MTR, sampling the steel bar connection situation and assessing the structural safety. Finally, the failure rate of the steel bar connection on the platform slabs of the east-west corridor and the north-south corridor was 36.6% and 33.2%, respectively. In addition, a total of 15.5% of the steel bars were completely untwisted into the screw caps.
Xia Zhengmin, the chairman of the committee, asked whether the bearing capacity of the incompletely connected steel bars should be ignored except for the steel bars that are butted at the ends. Liu Zhihong said that if the bearing capacity of some connection bars is to be calculated in the future, it needs to be researched and tested, which currently does not meet its requirements.
As for the joints between the platform and the continuous wall, Liu Zhihong said that there were weaknesses in the design. The 1.2-meter-thick continuous wall needs to support the 3-meter-thick platform. He went on to say that in the offshore area, in extreme cases, cracks may appear on the top of the continuous wall, causing water seepage. Under the influence of the salt and acidity of the seawater, the steel tends to rust and affect the durability.
Earlier in the hearing, it was mentioned that MTR had inspected the installation of Shear links on the east and west corridor floors. Of the 40 checkpoints, 16 did not have shear bars. Leighton's independent expert Southward wrote The testimony stated that the scope of the excavated stone excrement was small and it was not confirmed that there was no shear bar.
[Sandline] No shear bar was found at 16 positions on the platform floor.
[Sand Central Line] Leighton appointed experts: Reinforcement works or damage to reinforced screw caps, twist 6 safety
[Sand Central] Leighton, Commission Expert Reopening at Hearing: Reinforcement or Impact on Security
Reinforcing steel bars at Hung Hom Station on the Shazhong Line
