Fire resistance performance of submerged floating tunnel under various fire conditions

Submerged Floating Tunnels (SFT) were researched by countries had many island as Norway, Italy,\ud China, and Japan. Several sites were examined in China and Norway. Most of them investigated about seismic, dynamic,\ud and collision performance. However, present researches lack to apply the construction fields, therefore, additional\ud researches need. Fire resistance performance of the SFT is important one of the various researches. If fire break out in\ud SFT, it is damaged by thermal loads. The damage of the SFT varies by type of fire. Structure of the SFT is able to\ud collapse partially by fire scale and fire exposure time. For this reason, fire resistance design of the SFT must be\ud suggested. Fire resistance performance of SFT could be investigating for fire resistance design of SFT. Fire condition\ud could be expressed fire curves which are suggested by fire scale and fire exposure time. In this paper, temperature\ud distributions of the SFT were investigated through FE analysis under various fire conditions. Heat transfer analysis was\ud applied to investigate conduction of heat by fire. And there was to draw the biggest influence fire condition to the SFT\ud from FE analysis results. Also, preliminary study was performed for fire resistance design

Random wave loads on a long detached breakwater considering diffraction

Battjes (1982) found the loads of short-crested random waves on a long structure decrease with the structure length and also with the obliqueness of wave incidence. These decreases come from the spatial phase difference along the structure. Lee et al. (2010) found that obliquely incident random waves in a nearshore area become directionally asymmetric due to refraction. They also found the asymmetry becomes more significant in shallower waters. Recently, Jung et al. (2011) studied random wave loads on a long structure considering diffraction and directional asymmetry. In this study, we further study random wave loads on a detached breakwater considering diffraction of waves which propagate at both ends of the breakwater. We also consider directional asymmetry. The structure may be placed along the bottom contours in order to protect on-shore incoming waves. In that case, refraction induced random waves may become asymmetric, i.e., on-shore components are more dominant than along-shore ones. Therefore, directional obliqueness on the structure becomes less and thus the wave loads decrease in less degree than the symmetric waves. When waves are obliquely incident on a long structure, the diffract ing waves give forces on the lee side of the structure. The diffracting wave has a spatial phase variation along the lee side which is different from that the obliquely incident wave has on the front side. Thus, the wave loads decrease with the existence of diffract ing waves and also the phase difference between the incident and diffracting waves

Extreme waves generated by Typhoon Bolaven (201215) in Southern Korean waters

Unusual extreme waves were generated by Typhoon Bolaven (201215) in the Southern Korean Waters\ud (SKW) and gave destructive damages to the breakwaters of Seogwipo Harbor at Jeju Island. The waves were far\ud exceeding the design wave height (Hs50yrs 9.3m) and their duration was 14hours. The duration is a very significant\ud factor as much as the design wave height for breakwater armor stability in terms of cumulative damages. A significant\ud increase in strong typhoon intensity and duration in North West Pacific (NWP) due to global warming has been reported\ud and also in landfall typhoons on Korea/Japan in a recent decade. The frequency of typhoon passed SKW region had an\ud inter-annual and also a decadal variation and decreased in recent years, but several strong typhoons were occurred.\ud Bolaven was affected by high pressure distribution located above the warm eddy region to track toward NNW rather\ud than NE as usual in August. The extreme waves were analyzed with respect to typhoon genesis, evolution of the waves\ud through extensive measured data and model simulation. Numerical models of TC96 for the wind fields and WAM4.5.2\ud for the waves were used after calibration with measured data and correction of Cd in wave growth term. They produced\ud reasonably good results. It was found that the extreme waves were evolved by combination of distant large swell and\ud strong wind seas generated by consistent strong winds from front right quadrant of typhoon track for such a long time.\ud The variation of those waves was relatively small as 1-2m, which might be due to limitation of wave growth for\ud U>30m/s and bottom energy dissipation of long period waves in the region. It is essential to hindcast accurately the\ud extreme waves for design of the breakwaters and also for assessment of coastal flooding and coastal erosion in a\ud warming climate

Transient response analysis of a submerged floating tunnel under seismic and wave excitations

In this study, a numerical procedure is described for the transient response analysis of a submerged\ud floating tunnel with reference of a designed tunnel in Japan. Tension legs seizing the tunnel are simply modeled by a\ud spring elements and the tunnel itself is assumed by two rigid bodies between which a flexible joint is used. A recorded\ud seismic excitation is used while the wave load is calculated under a specific design condition. Hydro-damping and\ud added mass are considered for numerically modeling the underwater condition. A numerical procedure is validated with\ud compared to the previous results of the designed tunnel. Some modifications are proposed through the validating\ud process in terms of modeling and analysis procedure. Eventually, the modified numerical procedure will be used in\ud analyzing the transient response of a newly designed tunnel

Bending strength analysis of steel-composite submerged floating tunnels

A submerged floating tunnel (SFT) must have enough strength to resist to various external loadings such\ud as bending, torsion, tension, and compression. The expected main deformation of SFT is caused by bending moment.\ud And this bending moment makes tensile stress and compression stress on the wall of SFT. Thus, bending moment is a\ud main affecting factor on the safety of SFT. Until now, a reinforced concrete tunnel was suggested for SFT by other\ud researchers. In this study, an internally confined hollow reinforced concrete tunnel and a double skinned composite\ud tubular tunnel were proposed. And their bending strengths were studied and compared with that of a reinforced concrete\ud tunnel. The analysis results showed the proposed SFT structures had enough strength to guarantee safety

Search for TeV Scale Physics in Heavy Flavour Decays

The subject of heavy flavour decays as probes for physics beyond the TeV scale is covered from the experimental perspective. Emphasis is placed on the more traditional Beyond the Standard Model topics that have potential for impact in the short term, with the physics explained. We do unabashedly promote our own phemonenology work.Comment: 10 pages, 9 figures (now fixed); Submitted for the SUSY07 proceeding

Using Subsystem MT2 for Complete Mass Determinations in Decay Chains with Missing Energy at Hadron Colliders

We propose to use the MT2 concept to measure the masses of all particles in SUSY-like events with two unobservable, identical particles. To this end we generalize the usual notion of MT2 and define a new MT2(n,p,c) variable, which can be applied to various subsystem topologies, as well as the full event topology. We derive analytic formulas for its endpoint MT2{max}(n,p,c) as a function of the unknown test mass Mc of the final particle in the subchain and the transverse momentum pT due to radiation from the initial state. We show that the endpoint functions MT2{max}(n,p,c)(Mc,pT) may exhibit three different types of kinks and discuss the origin of each type. We prove that the subsystem MT2(n,p,c) variables by themselves already yield a sufficient number of measurements for a complete determination of the mass spectrum (including the overall mass scale). As an illustration, we consider the simple case of a decay chain with up to three heavy particles, X2 -> X1 -> X0, which is rather problematic for all other mass measurement methods. We propose three different MT2-based methods, each of which allows a complete determination of the masses of particles X0, X1 and X2. The first method only uses MT2(n,p,c) endpoint measurements at a single fixed value of the test mass Mc. In the second method the unknown mass spectrum is fitted to one or more endpoint functions MT2{max}(n,p,c)(Mc,pT) exhibiting a kink. The third method is hybrid, combining MT2 endpoints with measurements of kinematic edges in invariant mass distributions. As a practical application of our methods, we show that the dilepton W+W- and tt-bar samples at the Tevatron can be used for an independent determination of the masses of the top quark, the W boson and the neutrino, without any prior assumptions.Comment: 47 pages, 9 figures. revised version, published in JHEP. Major addition: a new appendix with the complete set of formulas for the MT2 endpoints as functions of the upstream transverse momentum pT and test mass M

Toward Green Synthesis of Graphene Oxide Using Recycled Sulfuric Acid via Couette-Taylor Flow

Developing eco-friendly and cost-effective processes for the synthesis of graphene oxide (GO) is essential for its widespread industrial applications. In this work, we propose a green synthesis technique for GO production using recycled sulfuric acid and filter-processed oxidized natural graphite obtained from a Couette-Taylor flow reactor. The viscosity of reactant mixtures processed from Couette-Taylor flow was considerably lower (???200 cP at 25 ??C) than that of those from Hummers' method, which enabled the simple filtration process. The filtered sulfuric acid can be recycled and reused for the repetitive GO synthesis with negligible differences in the as-synthesized GO qualities. This removal of sulfuric acid has great potential in lowering the overall GO production cost as the amount of water required during the fabrication process, which takes a great portion of the total production cost, can be dramatically reduced after such acid filtration. The proposed eco-friendly GO fabrication process is expected to promote the commercial application of graphene materials into industry shortly