Penetration and Removal of the Mooring Dolphin Platform With Three Caisson Foundations

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Puyang Zhang ◽  
Hongyan Ding ◽  
Conghuan Le
Keyword(s):  
Skin Friction ◽  
Strain Difference ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Soil Disturbance ◽  
Triaxial Tests ◽  
Soil Pressure ◽  
Lateral Earth Pressure ◽  
Caisson Foundations ◽  
Factor Α

Mooring dolphin platforms (MDPs) with three caisson foundations were installed in the ice-drifting Bohai Sea of China. Before installation, prototype tests of penetration and removal processing were conducted near the design site. To determine the lateral soil pressure and skin friction of the caisson, soil pressure and strain gauge transducers were fixed along the external skirt of caisson B of MDP1. The shaft skin friction was calculated from the strain difference between any two points of the strain gauges. The transducer results indicated that when the soil property determined by unconsolidated and undrained (UU) triaxial tests was used to calculate the unit skin friction resistance, a value of the adhesion factor α of 1.5–2.0 is recommended. The factor α is 1–0.4 during the suction-assisted penetration phase. The lateral earth pressure coefficient K decreased with penetration depth, most likely due to seepage caused by underpressure. In addition, the difference between the measured values obtained from the soil pressure transducers represented the small tilt of MDP1 during the installation phase. The skin friction and lateral earth pressure significantly decreased in the removal phase, 12 h after the penetration phase, mainly due to the soil disturbance caused by suction penetration around the caisson.

Lateral Earth Pressure Coefficient of Soils Subjected to Freeze–Thaw

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Saturated Soil ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Lateral Earth Pressure ◽  
Soil Deposits ◽  
Earth Pressure Coefficient ◽  
Water Saturated

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.

scholarly journals Experimental Study on At-rest Lateral Earth Pressure Coefficient of Cemented Clay

2019 ◽  
Vol 304 ◽  
pp. 042014
Author(s):  
Zhiqiang Wu ◽  
Zhengyin Cai ◽  
Kai Xu ◽  
Yunfei Guan ◽  
Yinghao Huang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Lateral Earth Pressure ◽  
Earth Pressure Coefficient

Analytical solution for active pressure of narrow backfills considering arching effect

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sahar Ghobadi ◽  
Hadi Shahir
Keyword(s):  
Analytical Solution ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Back Surface ◽  
Active Earth Pressure ◽  
Soil Pressure ◽  
Principal Stresses ◽  
Content Type ◽  
Arching Effect ◽  
Lateral Earth Pressure

Purpose The purpose of this paper is to study the distribution of active earth pressure in retaining walls with narrow cohesion less backfill considering arching effects. Design/methodology/approach To this end, the approach of principal stresses rotation was used to consider the arching effects. Findings According to the presented formulation, the active soil pressure distribution is nonlinear with zero value at the wall base. The proposed formulation implies that by increasing the frictional forces at both sides of the backfill, the arching effect is increased and so, the lateral earth pressure on the retaining wall is decreased. Also, by narrowing the backfill space, the lateral earth pressure is extremely decreased. Originality/value A comprehensive analytical solution for the active earth pressure of narrow backfills is presented, such that the effects of the surcharge and the characteristics of the stable back surface are considered. The magnitude and height of the application of lateral active force are also derived.

Study on Lateral Earth Pressure Coefficient at Rest for Frozen Soils

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Xiaoliang Yao ◽  
Jilin Qi ◽  
Fan Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Negative Temperature ◽  
Frozen Soil ◽  
Dominant Factor ◽  
Frozen Soils ◽  
Testing Conditions ◽  
Triaxial Apparatus ◽  
Lateral Earth Pressure ◽  
Earth Pressure Coefficient

The lateral earth pressure coefficient at rest, K0, is an important parameter in geotechnical engineering. There have been many studies for unfrozen soils; however, this is not the case for frozen soils, which impedes reasonable calculation concerning cold regions engineering. This paper introduces a novel triaxial apparatus for frozen soils with reference to that for unfrozen soils. The device is capable of performing experiments on frozen soil samples with K0 status under precisely controlled negative temperature. Two soils along the Qinghai-Tibetan highway are taken as study objects. K0 experiments are carried out with the apparatus and K0 is obtained under different testing conditions. It is found that temperature is a dominant factor in influencing K0 of frozen soils, while stress state and soil type should also be taken into account.

Study on Lateral Earth Pressure of Anchored Retaining Wall

2013 ◽  
Vol 353-356 ◽  
pp. 312-317
Author(s):  
Ying Yong Li ◽  
Li Zhi Zheng ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Zhi Chao Xue
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Model Test ◽  
Retaining Wall ◽  
Field Tests ◽  
Earth Pressure ◽  
Soil Pressure ◽  
Gravity Retaining Wall ◽  
Lateral Earth Pressure ◽  
The Stability

In order to ensure the security of gravity retaining wall in the high fill subgrade, the design of gravity retaining wall with anchors is proposed,the characteristic of the new wall is that comment anchors are added to the traditional gravity retaining wall,by friction anchors provide lateral pull to the wall so the stability of the new wall is improved. Because of the constraints of anchors, the lateral free deformation is influenced and the soil pressure distribution is very complicated, field tests showed that soil pressure distribution is nonlinear and pressure concentrate in anchoring position. In order to reveal the supporting mechanism of retaining wall and propose the soil pressure formula, the model test of anchor retaining wall is made and numerical simulation is done. The results show that soil pressure appears incresent above the anchor and decreasing below the anchor, the soil pressre also grew larger away from the anchor proximal in the horizontal direction.

K0 of sand measured by a plane-strain apparatus

2007 ◽  
Vol 44 (8) ◽  
pp. 1006-1012 ◽  
Author(s):  
Dariusz Wanatowski ◽  
Jian Chu
Keyword(s):  
Linear Relationship ◽  
Plane Strain ◽  
Void Ratio ◽  
Earth Pressure ◽  
Triaxial Tests ◽  
Preparation Methods ◽  
One Dimensional ◽  
Lateral Earth Pressure ◽  
Compression Behaviour ◽  
The One

Experimental results are presented in this note to study the coefficient of lateral earth pressure at rest, K0, of sand measured using a plane-strain apparatus. The data are also compared with the K0 measured by triaxial K0 consolidation tests. The test data show that the K0 values measured for specimens prepared using the water sedimentation method vary little with the void ratio of the soil, and therefore do not agree with the K0 values calculated using Jaky’s equation, which uses the peak friction angles obtained from either plane-strain or triaxial tests. The K0 values measured for specimens prepared using the moist tamping method follow a linear relationship with the void ratio. However, this relationship does not agree with Jaky’s equation either. The K0 values obtained from tests on the specimens prepared using the two different preparation methods are different, which may reflect the influence of soil fabrics or structures on the one-dimensional compression behaviour of soil.

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