Centrifuge Study of the Effects of Lattice Leg on Penetration Resistance and Bearing Behavior of Spudcan Foundations in NC Clay

2012 ◽  
Author(s):  
Yu Ping Li ◽  
Fook Hou Lee ◽  
Siang Huat Goh ◽  
Jiang Tao Yi ◽  
Xi Ying Zhang
Keyword(s):  
Bearing Capacity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Clay ◽  
Penetration Resistance ◽  
Cavity Depth ◽  
Circular Column ◽  
Model Study ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

This paper reports the primary results of a centrifuge model study into the possible effects of the lattice leg on the penetration resistance and vertical bearing capacity of spudcan foundations in normally consolidated clay. Up to now, the possible effects of the lattice leg has been largely ignored in both research and design of spudcan foundation. Centrifuge experimental results show that there is an increase in penetration resistance for spudcan footing equipped with lattice leg, in comparison with spudcan footing connected to slender circular column leg as widely used by current research. Larger excess pore water pressure was generated by the spudcan penetration with lattice leg in compare with that without. Moreover, the presence of the lattice leg is shown to affect the cavity depth formed around the penetrated spudcan footing, which is simply assumed completely back flow for spudcan penetration in soft clay by SNAME (2008). It was found that the bearing capacity of spudcan foundation has been further underestimated by SNAME (2008) due to the neglecting of lattice leg effect. Taken altogether, this implies that changes in penetration resistance arising from the lattice leg may be due to the effect of the latter on the backflow pattern. Apart from highlighting the effect of the sleeve with big openings, the results also highlight the possible future use of sleeves to enhance the bearing capacity and possibly reduce the penetration of spudcan foundations in various soil deposits.

scholarly journals Undrained vertical bearing capacity of pile located near soft clay slope

2015 ◽  
Vol 3 (3) ◽  
Author(s):  
Mehrab Jesmani ◽  
Ali Kasrania ◽  
Mehrad Kamalzare ◽  
Iman Mehdipour
Keyword(s):  
Bearing Capacity ◽  
Soft Clay ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

scholarly journals Numerical analysis for the vertical bearing capacity of composite pile foundation system in liquefiable soil under sine wave vibration

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248502
Author(s):  
Huang Zhan-fang ◽  
Xiao-hong Bai ◽  
Chao Yin ◽  
Yong-qiang Liu
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Water Pressure ◽  
Seismic Loading ◽  
Shaking Table ◽  
Pile Spacing ◽  
Liquefiable Soil ◽  
Composite Pile ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

Composite pile foundation has been widely used in ground engineering. This composite pile foundation system has complex pile-soil interactions under seismic loading. The calculation of vertical bearing capacity of composite pile foundation is still an unsolved problem if the soil around piles is partially or completely liquefied under seismic loading. We have completed indoor shaking table model tests to measure the vertical bearing capacity in a liquefiable soil foundation under seismic loading. This paper will use a numerical approach to analyze the change of this vertical bearing capacity under seismic loading. Firstly, the Goodman contact element is improved to include the Rayleigh damping. Such an improvement can well describe the reflection and absorption of seismic waves at the interface of soil and piles. Secondly, the Biot’s dynamic consolidation theory incorporated an elastoplastic model is applied to simulate the soil deformation and the generation and accumulation of pore water pressure under seismic loading. Thirdly, after verification with our indoor shaking table test data, this approach is used to investigate the effects of pile spacing on liquefaction resistance of the composite pile foundation in liquefiable soil. The time histories of pore water pressure ratio (PPR′) are calculated for the liquefiable soil and the vertical bearing capacity in partially liquefied soil is calculated and compared with our indoor shaking table test data at the 3D, 3.5D, 4D, 5D and 6D cases (D is the pile diameter). It is found that the pile spacing has some influence on the extent of soil liquefaction between piles. The vertical bearing capacity varies with liquefaction extent of inter-pile soil. The optimization of pile spacing varies with liquefaction extent. These results may provide some reference for the design of composite pile foundation under seismic loading.

Study on Reinforce Saturated Soft Clay Foundation with Dynamic Consolidation by Drainage

2013 ◽  
Vol 438-439 ◽  
pp. 1171-1175
Author(s):  
Zhi Li Sui ◽  
Zhao Guang Li ◽  
Xu Peng Wang ◽  
Wen Li Li ◽  
Tie Jun Xu
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Clay ◽  
Soil Layer ◽  
Good Effect ◽  
Loading Test ◽  
Test Plate ◽  
Dynamic Consolidation ◽  
Saturated Soft Clay

Dynamic consolidation method has been widely used in improving soft land, but always inefficient to saturated soft clay land, which is hard to improve, and even leads to rubber soil. Dynamic and drain consolidation method will deal with it well, with drainage system, pore-water can be expelled instantly from saturated soft clay as impacting. The pore-water pressure and earth pressure test in construction, the standard penetration test, plate loading test, geotechnical test after construction, which are all effective methods for effect testing. There is a comprehensive detection through different depth of soil layer with different detecting means on construction site. The results show that improving saturated soft clay land with dynamic and drain consolidation method has obtained good effect, and the fruit can be guidance for such construction in the future.

Research on Simulation of Land Subsidence Characteristics under the Groundwater Level Fluctuation

2013 ◽  
Vol 368-370 ◽  
pp. 1697-1700
Author(s):  
Long Zhang ◽  
Xue Wen Lei ◽  
Qing Shang Meng
Keyword(s):  
Finite Element ◽  
Land Subsidence ◽  
Groundwater Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Clay ◽  
Level Fluctuation ◽  
Finite Element Software ◽  
Coastal Cities ◽  
Groundwater Level Fluctuation

Based on the characteristics of frequent land subsidence events caused by groundwater level fluctuation in coastal cities in China and studying on the quaternary sedimentary soft clay in Shanghai, the effects of groundwater level fluctuation on the deformation of soft clay is simulated by Geo-Studio finite element software. It has summarized the law of deformation, effective stress with the change of groundwater level fluctuation, especially the process of dissipation of pore water pressure with the groundwater level fluctuation. The low can be sued as a reference for similar engineering and land subsidence prevention.

scholarly journals Effect of shaft rotation of spiral piles under its installation on vertical bearing capacity

2015 ◽  
Vol 10 (2) ◽  
pp. 253-265
Author(s):  
Takahiro SATO ◽  
Takeo HARADA ◽  
Naoto IWASA ◽  
Satoshi HAYASHI ◽  
Jun OTANI
Keyword(s):  
Bearing Capacity ◽  
Shaft Rotation ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity
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