In October, 2017, a series of wildfires attacked Northern California. The reasons of these fires are the long time high temperature, the longtime drought, the fast population growth and the terrible diablo winds. The maximum wind speed can up to 113 mph, which is much faster than the speed that the firemen put out the fires and the speed that the local inhabitants run away.
The 1km Mersey Gateway Bridge is the centerpiece of the construction work across Halton, which lasts more than three and a half years. The Mersey Gateway Bridge connect the towns of Widnes and Runcorn that are near the neck of the Mersey estuary. The total length of this bridge is 2,248m. It is made up of two viaducts on either side of a 1km six-lane-cable-stayed span.
Brexit has not only brought uncertainty to UK politics, but also affected the country's economic development, the depressed growth rate of construction industry is just a typical example. The economic director of UK Construction Products Association said that UK construction output is slowing, and there are signs predict that the construction industry will facing a tough winter next year. On the contrary, Australia's construction industry has advanced by leaps and bounds among this year, infrastructure, commercial buildings and residential buildings growing savagely, making the Australian Performance of Construction Index (PCI) increased by 4.5 points to 60.5 in July 2017, which represents the highest level in 12 years.
Rock Bolt is one of effective supporting methods to reinforce foundation of civil construction. It relies on bonding strength between soil layer and rock bolt structure to provide bearing capacity. It is widely applied in engineering structures which needs stress to transfer in stable soil body.
The fundamental principle of geotechnical anchoring is to transfer tension of structures or keep self stability of excavation face in stratum, relying on shearing strength of self drilling rock bolt’s surrounding stratum.
As self drilling bolt’s raw material, seamless steel tube’s quality must be completely inspected according to product standard and technical specification. Specific inspection includes steel tube’s chemical component analysis, geometric dimension inspection, surface quality inspection, physical and chemical properties inspection, processing property inspection, metallographic analysis, thread inspection and measurement. The purpose is to ensure quality of steel tube and meet relevant standard code or technical condition requirement.
During tunnel construction, deformation often happens. Observing from tunnel surface, there are cracks, shedding phenomenon or underground water dropping appearing. If reason doesn’t get analyzed and maintained timely, worse deformation will happen.
Self drilling anchor system’s inclination should be 15°~25° horizontal downward, no large than 45°. With increase of inclination, horizontal component of self drilling anchor system decreases. Too large inclination will reduce anchoring effect and increase vertical component on supporting structure, which will also cause settlement of retaining structure and surrounding foundation. To use self drilling anchor system’s pulling resistance effectively, self drilling anchor system should parallel with direction of side pressure effect.
The TBM boring the Los Condores Hydroelectric Power Plant has completed the 900m access tunnel and is working on the first section of the headrace tunnel. The machine, a 4.56m Robbins double shield, has so far excavated 1,300m.
The 6.7km long, 9.9m diameter twin Bolaños rail tunnels have been completely bored on the Madrid-Galicia High-Speed Line for client in Spain.