scholarly journals Laboratory study on response of underwater cohesive sediment to columnar vibration source

2018 ◽  
Vol 54 (3) ◽  
pp. 193-202
Author(s):  
Peng Zhao ◽  
Feier Chen ◽  
Guoliang Yu
Keyword(s):  
Pressure Distribution ◽  
Experimental Observation ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Near Field ◽  
Mechanical Vibration ◽  
Cohesive Sediment ◽  
Vibration Source ◽  
Soil Pressure

Abstract This paper investigates the responses of cohesive sediment to mechanical vibration by experimental observation, containing: (1) the dynamic soil pressure, dynamic pore water pressure and dynamic acceleration to the vibration source; (2) the soil pressure distribution in the near field centered in an artificial columnar vibration source. Under the mechanical vibration with a frequency of 200 Hz and an amplitude of 1.15 mm, the dynamic soil pressure, dynamic pore water pressure and dynamic acceleration of underwater viscous sediment were measured in the sediment of four different depositing conditions. Results of the dynamic soil pressure, dynamic pore water pressure and dynamic acceleration of underwater viscous sediment in the near field responding to artificial vibration source are exhibited and discussed. It is found that, excited by the sinusoidal vibrator, the soil pressure presents a response of statistical sinusoidal fluctuation with the same frequency to the vibration source. In the sediment of lower initial yield stresses, the soil pressure distribution distinctly tends to firstly increase and then decrease with distance. The amplitude of the soil pressure is attenuated exponentially with distance.

The Test Study to the Changes of Excess Pore Water Pressure during Precast Pile Construction

2012 ◽  
Vol 193-194 ◽  
pp. 1010-1013
Author(s):  
Shu Qing Zhao
Keyword(s):  
Pore Water ◽  
Clayey Soil ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Excess Pore Pressure ◽  
Soil Pressure ◽  
Excess Pore Water Pressure ◽  
Test Study ◽  
Excess Pore

The construct to precast pile in thick clayey soil can cause the accumulation of excess pore water pressure. The high excess pore pressure can make soil, buildings and pipes surrounded have large deflection, even make them injured. Combining with actual projects, this paper presents an in-situ model test on the changes of excess pore water pressure caused by precast pile construct. It is found that the radius of influence range for single pile driven is about 15m，the excess pore water pressure can reach or even exceed the above effective soil pressure, and there are two relatively stable stages.

In Situ Study on Soil Disturbance Induced by Shield Tunneling in Tianjin

2013 ◽  
Vol 368-370 ◽  
pp. 1674-1677
Author(s):  
Yong Hua Cao ◽  
Xiao Qiang Kou
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Disturbance ◽  
Ground Settlement ◽  
Soil Pressure ◽  
Shield Tunneling ◽  
Tunnel Face ◽  
Tunneling Process

In urban environment, the soil disturbance induced by shield tunneling can be sensitive because it can cause deformation of the ground and damage the near structure. To study this disturbance in the construction process of Tianjin metro line No.3, in-situ monitoring of pore water pressure, soil pressure and ground settlement were conducted. The pore water pressure was monitored for the soil around the tunnel. The soil pressure was monitored for the soil around the tunnel and on the tunnel face. It was revealed that the pore water pressure and soil pressure changed twice in the tunneling process and these changes were induced by cutting face and grouting at the shield tail. The soil pressure on the tunnel face reached its maximal value when the distance between the cutting face and the sensor elements was around the diameter of the tunnel. Ground settlement developed in the tunneling process. The shape of ultimate settlement trough is closed to the one obtained by Pecks method.

Pore Water Pressure Distribution and Dissipation During Thaw Consolidation

2016 ◽  
Vol 116 (2) ◽  
pp. 435-451 ◽  
Author(s):  
Xiaoliang Yao ◽  
Jilin Qi ◽  
Mengxin Liu ◽  
Fan Yu
Keyword(s):  
Pressure Distribution ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Thaw Consolidation

scholarly journals The Risk of Liquefaction Associated with Water Head Fluctuation in the Low-lying Area of Tokyo

2019 ◽  
Vol 8 (2) ◽  
pp. 41-47
Author(s):  
Tomohide Takeyama ◽  
Kazuya Honda ◽  
Atsushi Iizuka
Keyword(s):  
Pressure Distribution ◽  
Pore Water ◽  
Seismic Analysis ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Level ◽  
Flood Damage ◽  
Tokyo Bay ◽  
Ground Settlement ◽  
Groundwater Head

 In the wide area of the eastern part of Tokyo, the ground level is less than mean sea level. This area is more vulnerable to disasters than other areas. If large flood damage such as storm surge should occur in this area, the disaster would be a long-term catastrophe. On the coast of Tokyo Bay, countermeasures have been taken by tide embankments and floodgates. However, considering the damage scale when it occurs, an analysis in this area is very important. In this area, ground settlement occurred and groundwater head dropped because groundwater excessively withdrew by the industrial purpose during the period of economic growth. Currently, the groundwater head recovers and the ground settlement has been subsided. However, due to the groundwater head fluctuation, pore water pressure distribution had been different from hydrostatic pressure distribution. Therefore, in the analysis in this area, it is necessary to consider past groundwater head fluctuation. In this research, the ground settlement and the distribution of pore water pressure are simulated from groundwater level fluctuation over the past 100 years. Then, we conducted the seismic analysis by input the distribution of effective stress calculating from the simulated ground water pressure. The sites analyzed in this research are Tokyo Sea Life Park at the mouth of Arakawa River.

p–y curve and lateral response of piles in fully liquefied sands

2012 ◽  
Vol 49 (6) ◽  
pp. 633-650 ◽  
Author(s):  
Mohamed Ashour ◽  
Hamed Ardalan
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Near Field ◽  
Free Field ◽  
Overburden Pressure ◽  
Excess Pore Water Pressure ◽  
Lateral Response ◽  
Liquefied Soils ◽  
Excess Pore

This paper provides a technique to assess the response of laterally loaded piles and associated p–y curves in fully liquefied soils (where p is the soil–pile reaction and y is the pile deflection). The technique accounts for the variation of water pressure in the liquefied soils around the pile and its impact on the shape of the p–y curves and the pile lateral response. A constitutive undrained stress–strain model for fully liquefied saturated sands using the basic properties of sand is established to predict the post-liquefaction varying resistance of liquefied sands at different levels of loading assuming fully undrained conditions. The degradation in soil strength due to the free-field excess pore-water pressure (uxs,ff), caused by an earthquake and resulting in full liquefaction, is considered along with the near-field excess pore-water pressure (uxs,nf) induced by lateral loading from the superstructure. The presented procedure also accounts for the influence of the overburden pressure and sand density on the variation of excess water pressure in the near-field soil, the rebound of sand strength, and the shape of the p–y curve due to the dilative behavior of sands.

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