The Hong Kong-Zhuhai-Macao Bridge has a designed life span of 120 years. [EDMOND TANG/CHINA DAILY] The Hong Kong-Zhuhai-Macao Bridge, one of the most massive infrastructure projects ever undertaken, is being hailed as a remarkable achievement in cutting-edge civil engineering. International tunnel expert Tommy Olsen, from COWI, a leading infrastructure consulting company in Denmark, said its immersed tunnel sets a standard that may be copied in other projects around the world. One concept that Olsen's team brought to the Chinese project was watertight concrete, keeping the concrete tunnel safe from high hydraulic pressure without the need for waterproofing membranes. Such membranes cannot be guaranteed to last as long as 120 years, the designed life span of the bridge, Olsen said, but good quality concrete can. Olsen, who led a consulting team working with Chinese designers on the project, said the concept has been used for immersed tunnels in Europe and Korea, but the HZMB established new standards. This project is unique and what has been learned from this project could be applied to other long immersed tunnels worldwide in the coming years - like some of the concepts my team brought to this project, he said. Before joining the HZMB team, Olsen's company helped design the Busan-Geoje Fixed Link in South Korea and the Oresund Bridge linking Denmark and Sweden - two of the world's leading bridge-tunnel projects. After visiting the bridge site in February, after the principal sections were completed, Olsen told China Daily: I am very impressed when I see the quality of the job. I am quite impressed by what I have seen today. When it is constructed in this way and with high quality, there is much greater likelihood that the tunnel will not leak water for the next 120 years, which is a very long time span for a project. The intended 120-year life span of the bridge embraced talents supplied by the governments of Hong Kong, Macao and Guangdong province. The achievement is considered a high watermark of positive exchanges in civil engineering among the three jurisdictions. Lau Ching-kwong, a bridge expert in Hong Kong, credits this cooperation with ensuring the high quality of the bridge. Lau, a fellow of the Hong Kong Academy of Engineering Sciences, led the construction in the 1990s of the Tsing Ma Bridge in Hong Kong, the world's longest suspension bridge accommodating both rail and road traffic. He was also a member of the expert group advising on key technologies for the HZMB. The designed life span of a bridge on the Chinese mainland is normally 100 years, Lau said, but in Hong Kong it is 120 years. That was the standard set for the HZMB, which meant better materials were demanded. The same principle was applied to the standards for earthquake resistance, wind shear and every other index that defines a solid engineering structure, Lau said. It was a challenge for engineers in the three places, but Lau said, You can see that it worked out great. silicon wristbandssilicone wristbands edmontoncustom his and her braceletscheap custom braceletsembossed wristband
[Photo/VCG] A cancer patient with HIV may have been cleared of the virus after receiving a bone marrow transplant from an HIV-resistant donor, thought to be the second such case after a bone marrow transplant, according to research published in the journal Nature on Tuesday. The patient, whose identity was not disclosed, stopped taking antiretroviral drugs 16 months after the transplant, and the virus has not been detected during an additional 18 months, according to the study. In the research, led by Ravindra Gupta, an infectious diseases physician at the University of Cambridge in the United Kingdom, the patient received bone marrow stem cells from a donor with a rare genetic mutation known as CCR5 delta 32, which produces immunity to HIV infection, according to Nature. The first such case of an HIV patient being cleared of the virus after a bone marrow transplant happened a decade ago to Timothy Brown, known as the Berlin patient, who is still free of the virus. The breakthrough suggests the first case was not a one-off and could pave the way for future treatments, Nature said in a release on its website. Gupta described his patient as functionally cured and in remission. But he cautioned, It's too early to say he's cured, according to a Reuters report. The procedure is expensive, complex and risky, and will not be a common method to cure all patients with HIV, the report said.
