Jun-ichi Hoshikuma

Damage of Bridges due to the 2010 Maule, Chile, Earthquake

This article presents the damage of bridges resulting from the 2010 Maule, Chile earthquake based on site investigations. Features of bridge damage are presented and discussed with emphasis on the effect of in-plane rotation of skewed bridges, insufficient seat support length, absence of integrity of prestressed concrete girder bridges without diaphragms, and lack of bearing capacity of foundations.

SEISMIC RETROFIT OF EXISTING HIGHWAY BRIDGES IN JAPAN

Abstract This paper presents the current technical developments for seismic design and seismic retrofit of existing highway bridges in Japan. At first, the histories of the past seismic design codes, past seismic evaluation investigation, and past seismic retrofit practices for highway bridges are described. Then the damage caused by the 1995 Hyogo-ken Nanbu Earthquake and the lessons learned from the earthquake are briefly described. Finally, the seismic retrofit program after the Hyogo-ken Nanbu Earthquake is described with emphasis on research and development as well as field practice of the seismic retrofit of existing reinforced concrete highway bridges such as single column bent, wall-type pier, and multicolumn bents.

A study on seismic behavior of pile foundations of bridge abutment on liquefiable ground through shaking table tests

There is risk of bridge foundations to be damaged by liquefaction-induced lateral spreading of ground. Once bridge foundations have been damaged, it takes a lot of time for restoration. Therefore, it is important to assess the seismic behavior of the foundations on liquefiable ground appropriately. In this study, shaking table tests of models on a scale of 1/10 were conducted at the large scale shaking table in Public Works Research Institute, Japan, to investigate the seismic behavior of pile-supported bridge abutment on liquefiable ground. The shaking table tests were conducted for three types of model. Two are models of existing bridge which was built without design for liquefaction and the other is a model of bridge which was designed based on the current Japanese design specifications for highway bridges. As a result, the bending strains of piles of the abutment which were designed based on the current design specifications were less than those of the existing bridge.