Study on the treatments and countermeasures for liquefiable foundation

This paper summarizes the current treatments and countermeasures for liquefiable foundations, and divides the existing anti-liquefaction countermeasures into two categories. One of the ideas is proceeding from the properties of liquefiable foundation soils, by the means of improvement for the soil’s qualities to enhance the capacity of soil’s anti-liquefaction in the early stage. The other idea is considering from the stress conditions of liquefiable foundation soils, and to reduce the liquefaction-induced disasters by changing the stress conditions of the soil. The advantages and disadvantages of various anti-liquefaction measures were analysed by verifying the effectiveness of field applications of anti-liquefaction measures against ground liquefaction hazards, and the applicable conditions of various anti-liquefaction measures were classified. This paper provides experience for resisting soil liquefaction disasters.

SPATIAL SUSCEPTIBILITY OF ARCHAEOLOGICAL SITES TO EARTHQUAKE ENVIRONMENTAL EFFECTS (EEES)

The study examines a semi-quantitative indicator based method to assess the spatial susceptibility of archaeological sites to the secondary Earthquake Environmental Effects (EEEs) of ground liquefaction, landslides and tsunami. The method was applied at 16 archaeological sites allowing the identification of the EEEs each site is susceptible to and their prioritization at a national and regional level through the Spatial Susceptibility index (SSi). Results indicate that the majority of the sites are susceptible to at least one Earthquake Environmental Effect. This highlights their contribution to the vulnerability of archaeological sitesto earthquake hazard and the necessity for the integration of spatial susceptibility parameters in vulnerability assessment studies for cultural heritage protection.

Ground Liquefaction and Deformation Analysis of Breakwater Structures Under Earthquakes

Ground liquefaction and deformation is one of the important causes that damage engineering structures. Chinese current code for seismic design of breakwater is based on the single-level seismic design method as well as code for port and water-way engineering. However, this code can not exactly reflect the seismic performance of breakwater structures which experience different seismic intensities. In this paper, the author used a finite difference software, namely, FLAC3D, to analyze the state and compute seismic responses of breakwater structure. The breakwater foundation’s pore pressure ratio and displacement due to different earthquake have been studied. And the result show that: Smaller earthquakes have little influence on serviceability of the foundation, and severe earthquakes can liquefy some parts of the foundation; In the latter case , obvious changes of pores and foundation displaces can be found. Particularly, when seismic peak acceleration reachs 0.2g, Liquefaction appears in the foundation and mainly concentrated in the upper right side of the structure. In addition, the survey of ultra-hole pressure and displacement values of sand layers of the breakwater, manifests when the ultra pore pressure near 1.0, displacement and overturning structure is relatively large, resulting in varying degrees of damage to the structure. This paper’s research can provide theoretical and designable reference for similar engineering structures