Shaking Table Tests on Permanent Ground Displacement Due to Liquefaction

To study the mechanism of permanent ground displacement due to liquefaction, shaking table tests were conducted. Moreover, vane tests and cyclic torsional shear tests were carried out to measure the rate of decrease of the elastic modulus and the shear strength due to liquefaction. Based on these test results, the authors proposed a simplified procedure for the prediction of permanent ground displacement. Measures to counter permanent ground displacement were also discussed based on the analysis

Analyses of Liquefaction-Induced Deformation of Grounds and Structures by a Simple Method

The authors proposed a simple method to estimate liquefaction-induced deformation of grounds and structures. Adaptability of the method to the settlement of footings was studied. Centrifuge tests for the footing of transmission tower were selected to demonstrate the adaptability of the method. Analyses were carried out under the same conditions of the centrifuge tests. By comparing the analyzed results with the tested results, it was concluded that the effect of thickness of liquefied layer and soil density on the settlement of footing can be evaluated well by the simple method. Effect of countermeasures on the settlement of footing also could be evaluated well

Change of Waterline and Water Depth at Izmit Bay Due to 1999 Kocaeli Earthquake in Turkey

The 1999 Kocaeli Earthquake of August 17,1999 hit the western part of Turkey causing very great damages. From a result of our investigation and survey, typical geotechnical damages on this earthquake were pointed up except structural damage due to inertia force. One was a settlement andfor tilting of buildings induced by the ground deformation such as soil liquefaction or bearing failure in Adapazari City. Another was a widespread land loss in the south of coast in Izmit Bay, induced by the fault movement. In this paper we deal with the widespread land loss around Izmit Bay. The authors check into the relationship between the submerged area and the rupture of the fault, and then carried out the measurement of water depth at several cross sections of offshore in Izmit Bay. In order to clarify the aspect of loss of the coastal land, the topography of the seabed before and after the earthquake were compared. And then, some in-situ tests were conducted near the submerged area. From the result of the measurements, in-situ tests and the field survey, the causes of the loss of coastal land could be anticipated