Rare earthquake response spectra for typical site conditions in Hong Kong

Hong Kong is located in a region of low-to-moderate seismicity; the potential consequences in the event of a nearby major earthquake should not be underrated. In the past two decades, researchers have conducted many studies on this issue and it is now clear that design procedures should not be directly borrowed from other codes of practice without modifications. This paper aims at presenting the rare earthquake response spectra for typical rock and soil sites in Hong Kong, which form the basis of a seismic design procedure. The uniform hazard spectrum (UHS) for rock sites was obtained from seismic hazard assessment using probabilistic methods. Records from 16 boreholes, representing a wide range of local site conditions, were collected from different locations in Hong Kong. A site-specific response spectrum was then constructed based on the results of site response analyses. Moreover, the 16 site-specific response spectra have been grouped into four types based on the (initial) site natural periods, which allows convenient evaluation of the loading characteristics that are expected at different types of sites. Finally, the rare earthquake response spectra proposed for Hong Kong are compared with those constructed based on the Chinese code (GB) and the Eurocode (EC8).postprin

Acoustic absorption of hemp-lime construction

Hemp-lime concrete is a sustainable alternative to standard wall construction materials. It boasts excellent hygrothermal properties in part deriving from its porous structure. This paper investigates the acoustic properties of hemp-lime concrete, using binders developed from hydrated lime and pozzolans as well as hydraulic and cementicious binders. To assess the acoustic absorption of hemp-lime walls, as they are commonly finished in practical construction, wall sections are rendered and the resulting impact on absorption is evaluated. Hemp-concretes with lime-pozzolan binders display superior acoustic properties relative to more hydraulic binders. These are diminished when rendered, as the open surface porosity is affected, however hemp-lime construction offers the potential to meet standard and guideline targets for spaces requiring acoustic treatment