반복 T bar 시험

반복 T bar 시험

 

영신컨설턴트 (02) 529 8803 2020 1 ystcha@naver.com

 

연약지반에서 시료 채취가 어려워 현장시험이 경제적이다. T bar시험은 피에조콘 시험보다 단면적이 커 더 정확하고 반복하중을 받는 지반에서 적합하다.

 

설계 적용 : 해상 석션 앵커, 해상말뚝

 

The remoulded undrained shear strength, sur, is an important parameter in the design of suction anchors and for offshore slope stability analyses. For suction anchors, the remoulded undrained shear strength is a key parameter for calculation of the penetration resistance and the under pressure required for installation.

 

The remoulded undrained shear strength also influences the side shear resistance after penetration is completed (i.e "set-up") and thereby the holding capacity of an anchor.

 

For offshore slope stability analyses, the remoulded undrained shear strength will influence the failure mechanism and the progressive failure of a potential slide (DeGroot & Lunne, 2007).

 

In the design of offshore piles the sur value (or the sensitivity, ST, the ratio between the undisturbed shear strength, su and sur), is used to estimate the friction load during penetration (API, 2004). The sur value is also used in the design of torpedo piles (Medeiros Jr., 2010).

 

In the case of onshore tests the value of sur is generally obtained from vane tests. Recently, cyclic T-bar tests have been used to obtain the sur value, especially for offshore applications.

 

 

심도별 관입과 인발을 반복

 

 

T-bar 6 cyclic test.

 

 

 

반복시험에 따른 강도 감소

 

normalized the penetration resistance values cycles, q(n), the initial values, qin.

 

 

Normalized cyclic degradation curves, T bar