New Mechanical Model for Evaluating Bearing Capacity of Prestressed Pipe Piles in Soil: Effect of Soil Layer

2022 ◽  
Vol 50 (3) ◽  
pp. 20210559
Author(s):  
Rongbao Chen ◽  
Jichao Zhang ◽  
Zeyu Chen ◽  
Xiaoyu Zhang
Keyword(s):  
Bearing Capacity ◽  
Mechanical Model ◽  
Soil Layer

Model Test of Bearing Capacity of WasteTire Assembly Foundation on Soft Soil Layer

2021 ◽  
Vol 69 (7) ◽  
pp. 263-269
Author(s):  
Me ti ◽  
Tri Harianto ◽  
Abdul Rachman Djamaluddin ◽  
Achmad Bakri Muhiddin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soft Soil ◽  
Soil Layer

scholarly journals A Full-Scale Experimental Study of the Vertical Dynamic and Static Behavior of the Pier-Cap-Pile System

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jianlei Liu ◽  
Meng Ma ◽  
Flavio Stochino
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Dynamic Stiffness ◽  
Soil Layer ◽  
Low Frequency ◽  
Full Scale ◽  
Single Pile ◽  
Static Stiffness ◽  
Loading Test ◽  
Test Technique

The bearing capacity evaluation of bridge substructures is difficult as the static loading test (SLT) cannot be employed for the bridges in services. As a type of dynamic nondestructive test technique, the dynamic transient response method (TRM) could be employed to estimate the vertical bearing capacity when the relationship between static stiffness and dynamic stiffness is known. The TRM is usually employed to evaluate single piles. For the pier-cap-pile system, its applicability should be investigated. In the present study, a novel full-scale experimental study, including both TRM test and SLT, was performed on an abandoned bridge pier with grouped pile foundation. The test included three steps: firstly, testing the intact pier-cap-pile system; then, cutting off the pier and testing the cap-pile system; finally, cutting off the cap and testing the single pile. The TRM test was repeatedly performed in the above three steps, whereas the SLT was only performed on the cap-pile system. Based on the experimental results, the ratio of dynamic and static stiffness of the cap-pile system was obtained. The results show that (1) in the low-frequency range (between 10 and 30 Hz in this study), the dynamic stiffness of the whole system is approximately four times of that of a single pile; (2) the ratio of dynamic and static stiffness of the cap-pile system tested in the study is approximately 1.74, which was similar to other tested values of a single pile; (3) to evaluate the capacity of similar cap-pile system and with similar soil layer conditions by TRM, the value of Kd/Ks tested in the study can be used as a reference.

Effect of a Strong Middle Layer on Spudcan Penetration

2014 ◽  
Author(s):  
Wen Gao ◽  
Tom Harrup ◽  
Yuxia Hu ◽  
David White
Keyword(s):  
Bearing Capacity ◽  
Layer Thickness ◽  
Soft Clay ◽  
Soil Layer ◽  
Strength Ratio ◽  
Top Soil ◽  
Flow Mechanisms ◽  
Soil Flow ◽  
Jack Up ◽  
Peak Resistance

The rapid penetration of one or more of the foundations of a mobile jack-up rig into the seabed is an ongoing major problem in the offshore industry, with the potential to cause major damage to the structure and endangering any personnel on board. A recent example is the jack-up drilling rig Perro Negro 6 incident happened near the mouth of the Congo river in July 2013 with one of the rig’s crew of 103 reported missing and six others injured. This uncontrollable displacement is due to a form of failure known as punch through failure and commonly occurs on stratified seabed profiles. It has been reported that unexpected punch-through accidents have resulted in both rig damage and lost drilling time at a rate of 1 incident per annum with consequential costs estimated at between US$1 and US$10 million [1]. This paper presents the bearing capacity profiles and associated soil flow mechanisms of a common spudcan foundation penetrating into a three layer soft-stiff-soft clay soil through the use of large deformation finite element (LDFE) analysis. The Remeshing and Interpolation with Small Strain (RITSS) [2, 3] technique was implemented in the software package AFENA [4] to conduct the LDFE analysis. Both soil layer thickness and soil layer strength ratios were varied to study their effect on the spudcan penetration responses. The LDFE results of spudcan penetration into the soft-stiff-soft clay soils were calibrated by existing centrifuge test data. A parametric study was then conducted to study the bearing capacity responses and soil flow mechanisms during spudcan large penetrations by varying the soil layer strength ratio and relative layer thickness to the diameter of spudcan. It was found that there were three types of bearing responses during continuous penetration of spudcan: (a) when the top soft layer is relatively thin, the spudcan bearing response was similar to that of two layer soils with stiff over soft clays; (b) when the top soil layer thickness is medium, a peak resistance is observed when spudcan penetrates into the middle stiff layer followed by reduction; (c) when the soil layer is thick, the peak resistance occurs when spudcan gets into the bottom soft soil layer. The critical thickness of top soil layer is a function of soil strength ratio and middle stiff soil layer thickness. The bearing response types were also corresponding to the soil cavity formations during spudcan initial penetration.

Research on Bearing Capacity of Column Underpinning Joint of Frame Structure Moving

2011 ◽  
Vol 243-249 ◽  
pp. 426-430 ◽  
Author(s):  
Ai Hua Du ◽  
He Qi Tang
Keyword(s):  
Bearing Capacity ◽  
Mechanical Model ◽  
Frame Structure ◽  
Deep Beam ◽  
Interface Shear ◽  
Joint Stress ◽  
Failure Type ◽  
Before And After ◽  
Interface Slip ◽  
Two Stages

An experiment of sixteen frame column underpinning joints of frame structure moving was introduced, the experiment sample failure phenomena and failure type was obtained. The type was like “deep beam” failure type-“tension bar arch”, and the last failure place occurred on the interface of column and beam. Then, the underpinning joint stress mechanism and failure mode was determined based on the experiment’s conclusion. In addition, the failure course of joint was divided two stages which were before and after interface punching slip by theoretical analysis, for the stage before interface punching slip a space “tension-bar-arch” mechanical model was presented for the underpinning joint, then theoretical bearing capacity equation for this underpinning joint were obtained. At the same time, for the stage of interface after punching slip, the theory of interface shear was put into the analysis of joint, then interface bearing capacity equation was obtained for this stage. At last the height equation was obtained by the analysis of the stage of after interface slip.

scholarly journals A method of calculating the bearing capacity of sand pile composite foundations in a mucky soil layer considering consolidation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongtao Zhang ◽  
Yuqing Liu ◽  
Huiwu Luo ◽  
Peishuai Chen ◽  
Dejie Li ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Water Content ◽  
Effective Stress ◽  
Void Ratio ◽  
Soil Layer ◽  
Composite Foundation ◽  
Engineering Practice ◽  
Application Process ◽  
Sand Pile ◽  
Cavity Expansion Theory

AbstractIn engineering practice, the measured bearing capacity of a sand pile composite foundation in a mucky soil layer is much larger than the design value. Based on the sand pile construction and the load application process, a method of calculating the bearing capacity of the foundation based on the effective stress was proposed. Cavity diameter expansion in sand pile construction was simplified into a planar problem, and the cavity expansion theory was used to establish the expression of the rate of displacement and the horizontal stress increase. Based on the e–p curve and the calculation of the degree of consolidation, the relationships between the horizontal and vertical effective stress and the void ratio were obtained. According to the close relationship between the bearing capacity of the foundation in a mucky soil layer and the water content, an expression describing the relationships between the bearing capacity of the foundation, effective stress, void ratio, and water content was established. For the temporary engineering foundation treatment project, which needs a high bearing capacity but allows large foundation deformation, the design of sand pile composite foundations uses these relationships to take the consolidation effect of mucky soil into consideration, thereby reducing the replacement rate and lowering the construction cost.

Stabilization of Weak Clay with Strong Sand and Geogrid at Sand-Clay Interface

1998 ◽  
Vol 1611 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Braja M. Das ◽  
Kim H. Khing ◽  
Eun C. Shin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soil Layer ◽  
Granular Soil ◽  
Laboratory Model ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Base Course ◽  
Granular Base

The load-bearing capacity of a weak clay subgrade can be increased by placing a strong granular base course of limited thickness on top of the clay layer. The load-bearing capacity can be increased further, or the thickness of the granular base course can be reduced, by separating both layers by a geogrid. Laboratory model test results for the ultimate bearing capacity of a rigid strip loading on the surface of a granular soil underlain by a soft clay with a layer of geogrid at the interface of the two soils are presented. The optimum thickness of the granular soil layer and the critical width of the geogrid layer required to derive the maximum benefit from the reinforcement were determined. Model test results on the permanent settlement of the rigid strip load caused by cyclic loading of low frequency are presented.

Axial Pile Capacity Prediction Obtained from Environmental Friendly Jack-In Piling Test on Clayey Soil

2016 ◽  
Vol 845 ◽  
pp. 70-75
Author(s):  
Yusep Muslih Purwana ◽  
Niken Silmi Surjandari ◽  
Haryanto Wahyu
Keyword(s):  
Quality Control ◽  
Bearing Capacity ◽  
Axial Load ◽  
Clayey Soil ◽  
Soil Layer ◽  
Low Noise ◽  
Pile Capacity ◽  
Environmental Friendly ◽  
Minimum Disturbance ◽  
Capacity Prediction

Jack-in piling is environmental friendly system enabling placement of the pile into soil layer with minimum disturbance. It works with very low noise, low vibration, allows piling in confined area, relatively very fast in term of installation rate, better quality control and very fast in mobility. The main issue regarding the pile is bearing capacity; the ability of the pile to withstand axial load without failure. This study attempts to find the correlation between jack-in force and ultimate pile bearing capacity. The result of 5 piling record on clayey layer soil indicates that there is a good correlation between jack-in force and empirical ultimate pile bearing capacity.

scholarly journals PROPOSAL OF MECHANICAL MODEL FOR ESTIMATION OF RELATIONSHIP BETWEEN BEARING CAPACITY AND DEFORMATION OF MUD WALL BASED ON SOIL MECHANICS

2018 ◽  
Vol 83 (751) ◽  
pp. 1273-1283
Author(s):  
Mitsuhiro MIYAMOTO ◽  
Ryohei MIYATA ◽  
Takayuki OCHI ◽  
Naoki UTSUNOMIYA ◽  
Manabu MATSUSHIMA
Keyword(s):  
Bearing Capacity ◽  
Mechanical Model ◽  
Soil Mechanics

scholarly journals Effect of soil moisture content on the bearing capacity of small bored piles in the unsaturated soil of Maringá, Paraná, Brazil

2021 ◽  
Vol 337 ◽  
pp. 03006
Author(s):  
Verônica Ricken Marques ◽  
Antonio Belincanta ◽  
Mary-Antonette Beroya-Eitner ◽  
Jorge Luis Almada Augusto ◽  
Ewerton Guelssi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bearing Capacity ◽  
Water Content ◽  
Unsaturated Soil ◽  
Soil Layer ◽  
Matric Suction ◽  
Load Test ◽  
Degree Of Saturation ◽  
Static Load Test

In this study, the influence of soil moisture on the bearing capacity of piles founded in an unsaturated clay soil was investigated. The soil studied, composing the upper soil layer in Maringá, Brazil, is lateritic, has degree of saturation between 37% and 70% and has collapsible behaviour when wet. The bearing capacity was determined by full-scale load tests following the Brazilian Standard for Static Load Test. Two pile lengths, 4 m and 8 m, were considered. To analyse the influence of soil moisture, two tests were performed for each pile length: one in soil in its natural moisture content and another in pre-moistened soil. Results show that for both pile lengths, an increase in water content caused a significant reduction in bearing capacity, which is attributed to the decrease in the matric suction of the soil. This is confirmed by the results of the initial evaluation made on the variation of matric suction and its contribution to the bearing capacity with changes in water content. In summary, this study confirms that the pile bearing capacity in unsaturated soil is dependent on soil water content, highlighting the fact that the approach of assuming full saturation condition in the evaluation of the pile bearing capacity in such soil may give erroneous results. Moreover, this study demonstrate that the empirical methods most commonly used in Brazil for pile bearing capacity determination, the Décourt & Quaresma and Aoki & Velloso methods, are overly conservative when applied to the Maringá soil.

scholarly journals Reliability analysis of an end-bearing pile with account for friction forces on the pile surface

2020 ◽  
pp. 2-2
Author(s):  
Vladimir S. Utkin
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Limit State ◽  
Soil Layer ◽  
Material Behavior ◽  
Performance Criteria ◽  
Soil Behavior ◽  
Foundation Soil ◽  
Friction Forces ◽  
End Bearing Pile

Introduction. The behavior of end-bearing piles in the foundation soil and the methodology for their reliability analysis, treated as operational safety measures applicable to a separate bearing element of a pile foundation, need clarification and further development. The weakness of the established reliability analysis methodology, focused on the bearing capacity of the foundation soil, is its failure to take account of each case of the soil behavior above rock or low compressibility soils pursuant to Construction rules and regulations 24.13330.2011. Taking account of the bearing capacity of this soil layer in respect of the load accommodation by an end-bearing pile (taking account of the pile weight) may improve its reliability by the criterion of the bearing capacity in combination with the soil behavior below the bottom tip of a pile. Nizhne-Suyanskiy Waterworks Facility had the mission to solve water household, energy and socio-economic problems. Materials and methods. The author analyzed piles made of any applicable materials; their reliability analysis methods are based on the possibility theory due to the limited amount of statistical information on controllable parameters to be entered into the limit state design model to verify the bearing capacity of the foundation soil. Results. The author presents the design formula to identify the parameters ensuring reliable failure-free behavior of an end-bearing pile in the foundation soil and in respect of the soil bearing capacity. The pile reliability analysis performed in respect of its bearing capacity (and focused on the strength of the pile material) is provided in the references section. The author uses two performance criteria to analyze the reliability of an end-bearing pile, given that an end-bearing pile is analyzed as a consistent mechanical system in terms of the reliability theory. Conclusions. The author has developed a methodology used to analyze the reliability of end-bearing piles. It is focused on the bearing capacity of the foundation soil below the bottom tip of a pile and along its length with a view to the quantitative assessment of its safe performance at the stage of design of a facility that has a piled footing; the groundwork has been laid for further research into the behavior of end-bearing piles and for the development of design regulations applicable to various types of piles that may differ in material, behavior, sinking techniques, etc.

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