دانلود رایگان مقاله انگلیسی نشست و شیب ساختمان با فونداسیون های سطحی ناشی از روانگرایی - الزویر 2018

ABSTRACT

In order to examine relative importance of key parameters affecting liquefaction-induced settlement and tilting of buildings with shallow foundations, earthquake reconnaissance studies and centrifuge experiments were made and their results were compared with those of similar previous studies. It is shown that: (1) The liquefactioninduced relative settlement and tilting of shallow foundations tend to increase with increasing contact pressure and ground settlement, and with decreasing groundwater table depth and thickness of the non-liquefied crust; (2) The tilt angle of the building also tends to increase with increasing eccentric mass and distance ratio; and (3) The safety factors against vertical load and dynamic overturning moment are key indicators to estimate liquefaction-induced damage to buildings with rigid shallow foundations.

4. Concluding remarks

The field reconnaissance survey made in Karikusa town, Kumamoto, following the 2016 Kumamoto earthquakes demonstrated that:

1) Despite strong ground shaking, liquefaction-induced damage to building in the region was limited within a narrow stretch that was reportedly an old river channel about 400 years ago and later reclaimed artificially.

2) Difference in soil behavior within and outside of the liquefied zone was mainly due to the difference in soil type and stratification, i.e., sandy soils with Ic < 2 dominate near the ground surface within, while clayey soils with Ic > 2 prevail outside the liquefied zone.

3) The liquefaction-induced relative settlement and tilting of building in the liquefied belt were generally lower than those observed in other earthquakes. This was attributed to the many lightweight wooden houses of 2 stories in the region.

4) A few old wooden houses in the liquefied belt experienced damage to their superstructures, owing to their unreinforced weak foundation based on old design specification.