M E C H A N I S M O F C U T O F F W A L L O N S H A L L O W T U N N E L I N L I Q U E F I E D S O I L
Author(s):
Abstract:
Gradual increments of excess pore pressure in saturated soil layers during earthquakes lead to a decrease in effective stress and soil liquefaction. The damage caused by soil liquefaction is divided into three groups: surface damage, settlement damage, and underground structural damage. Generally, the first two cases are visible after the earthquake, regarding which extensive studies have been carried out. But, in the third group, because of the shortage of instrumented field evidence and the complexity of model investigation into underground structural damage caused by ground liquefaction, fewer studies have been implemented. The damage resulting from liquefaction may cause underground structures to be buoyant and settled due to decreases in the bearing capacity and increases in the lateral earth pressure. According to field evidence, linear structures such as tunnels may be destroyed by the liquefaction of ambient soils and uplift pressure. Thus, this phenomenon should be taken into consideration in the designing stage of tunnels. When the surrounding soil of the tunnel is liquefied, large deformations occur in the area, leading to an increase in the internal stresses and deformations of the lining. Thus, if liquefaction occurs in the surrounding soil of the tunnel, by improving its surrounding area, stresses and deformations can be controlled and their magnitudes can be reduced to an allowable limit. Therefore, evaluation of the liquefaction effects on the tunnel lining should be regarded as an important issue. In this research, the tunnel in the liquefied soil is modeled with Flac2D software, and in the liquefaction state, tunnel uplift and maximum internal forces of the tunnel lining are studied. In another model, cutoff walls are modeled on both side of the tunnel and their effects are studied. The studies show that a tunnel with cutoff walls reduces tunnel uplift and increase the internal forces of the tunnel lining. Then design parameters of cutoff walls, like wall thickness, wall length, and wall distance from the tunnel are evaluated.
Keywords:
Language:
Persian
Published:
Sharif Journal Civil Engineering, Volume:31 Issue: 2, 2015
Pages:
121 to 131
magiran.com/p1454648
دانلود و مطالعه متن این مقاله با یکی از روشهای زیر امکان پذیر است:
اشتراک شخصی
با عضویت و پرداخت آنلاین حق اشتراک یکساله به مبلغ 1,390,000ريال میتوانید 70 عنوان مطلب دانلود کنید!
اشتراک سازمانی
به کتابخانه دانشگاه یا محل کار خود پیشنهاد کنید تا اشتراک سازمانی این پایگاه را برای دسترسی نامحدود همه کاربران به متن مطالب تهیه نمایند!
توجه!
- حق عضویت دریافتی صرف حمایت از نشریات عضو و نگهداری، تکمیل و توسعه مگیران میشود.
- پرداخت حق اشتراک و دانلود مقالات اجازه بازنشر آن در سایر رسانههای چاپی و دیجیتال را به کاربر نمیدهد.
In order to view content subscription is required
Personal subscription
Subscribe magiran.com for 70 € euros via PayPal and download 70 articles during a year.
Organization subscription
Please contact us to subscribe your university or library for unlimited access!