Étude expérimentale de la capacité portante d'une couche de sol pulverulent d'épaisseur limitée

1987 ◽  
Vol 24 (2) ◽  
pp. 242-251 ◽  
Author(s):  
K. Siraj-Eldine ◽  
A. Bottero
Keyword(s):  
Bearing Capacity ◽  
Shape Factor ◽  
Finite Thickness ◽  
Testing Procedure ◽  
Semiempirical Methods ◽  
Foundation Soil ◽  
Capacity Coefficient ◽  
Capacité Portante ◽  
Soil Behaviour ◽  
Laboratory Models

This paper presents a series of experimental measurements of the bearing capacity of spread foundations resting on a layer of sand of finite thickness; they are carried out using circular or rectangular laboratory models. After an analysis of the graphical expression of results illustrating the foundation–soil behaviour under the applied load, we study the relationships between the bearing capacity coefficient and the different parameters of the problem: relative thickness of the compressible layer, interfacial foundation–soil and soil–substratum conditions of friction, shape factor of the models.In every case, the results have been compared with available results of other authors and related with existing theoretical or semiempirical methods; these comparisons lead to the proposal of a rational testing procedure for determining the ultimate load for shallow foundations. Key words: foundations, bearing capacity, interfaces, scale effect, shape factor, bilayer.

scholarly journals Soil behaviour under load in case of finite thickness

2020 ◽  
Author(s):  
Nihal D. Salman ◽  
György Pillinger ◽  
Péter Kiss
Keyword(s):  
Moisture Content ◽  
Bearing Capacity ◽  
Sandy Loam ◽  
Finite Thickness ◽  
Initial Density ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Push Down ◽  
Soil Bin ◽  
Soil Behaviour

AbstractThis study intends to examine the soil behaviour in the case of finite thickness, represented by the hard layer under a soft layer of soil. A further aim is to define load-bearing capacity parameters (n and k). The experimental work is carried out under laboratory conditions by using hydraulic bevameter to apply the load. A circular plate with a diameter of 100 mm is used to push down the load over the targeted area with a penetration rate of about 9 cm/min for sinkage plates. The study was conducted in a soil bin (length of 200 cm, width of 100 cm and variable thickness) using a sandy loam soil. First, the study has been done with loose soil with a thickness of 11 cm, which maintained with 10% moisture content and initial density of 1.190 g/cm3. After that, a two thickness of 6 and 18 cm with 8% moisture content and initial soil density of 1.375 g/cm3 were tested to explain the effect of thickness. In each test, the bevameter plate was loaded at multiple locations, the result showed the soil was near uniform. The result suggests that it is not easy to obtain one equation for the load bearing capacity because the layer near to the surface behaves like soil with infinite thickness and the deeper layer like soil with finite thickness.

scholarly journals Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand

Geosciences ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 392
Author(s):  
Maurizio Ziccarelli ◽  
Marco Rosone
Keyword(s):  
Bearing Capacity ◽  
Mechanical Behaviour ◽  
Failure Mechanisms ◽  
Shear Bands ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundations ◽  
Foundation Soil ◽  
Weak Layer ◽  
Geotechnical System ◽  
The Difference

The presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can affect the failure mechanisms, the ultimate bearing capacity of footings, and the safety factor of the geotechnical system. In this research, numerically conducted through Finite Element Code Plaxis 2D, the influence of a horizontal thin weak layer on the mechanical behaviour of shallow footings was evaluated. The obtained results prove that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than two to four times the footing width. In fact, under these circumstances, the failure mechanisms are always mixtilinear in shape because the shear strains largely develop on the weak layer. However, the reduction in the ultimate bearing capacity is a function of the difference between the shear strength of the foundation soil and the layer. The presence of a thin weak layer decreases the ultimate bearing capacity up to 90%. In conclusion, this research suggests that particular attention must be paid during detailed ground investigations to find thin weak layers. Based on the obtained results, it is convenient to increase the soil volume investigation to a depth equal to four times the width of the foundation.

Predicting the overall horizontal bearing capacity of jack-up rigs using deck–foundation–soil-coupled model

2020 ◽  
pp. 147509022092590
Author(s):  
Qilin Yin ◽  
Jinjin Zhai ◽  
Sheng Dong
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Double Layer ◽  
Soft Clay ◽  
Coupled Model ◽  
Single Layer ◽  
Horizontal Load ◽  
Foundation Soil ◽  
Failure Envelopes ◽  
Jack Up

The overall bearing capacity of a jack-up rig under horizontal load is conducted using finite element models that consider the deck–foundation–soil interaction. In these models, the simplified horizontal load acts on the deck and increases until the platform loses its stability. The effects of the self-weight of the platform W and load direction α on the ultimate horizontal bearing capacity Hult are investigated, and W- Hult failure envelopes under different α conditions are obtained. Two typical seabed types, including the double-layer seabed of sand overlying soft clay and the single-layer seabed of sand, are considered. The results show that a critical self-weight Wcritical exists in the double-layer seabed. Based on Wcritical, the failure of the platform presents two different modes. When W <  Wcritical, the windward leg is pulled up, and Hult increases with the increase in W. When W >  Wcritical, the failure mode is the leeward leg or legs puncturing the bearing sand layer, and Hult decreases with the increase in W. In the single-layer seabed, the failure mode is the windward leg being pulled up, and Hult increases with the increase in W throughout the whole range. The W- Hult envelopes in these two types of seabeds are basically the same when W <  Wcritical.

Experimental study of punching coefficients and shape factor for two-layered soils

1979 ◽  
Vol 16 (4) ◽  
pp. 802-805 ◽  
Author(s):  
A. J. Valsangkar ◽  
G. G. Meyerhof
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Shape Factor ◽  
Model Tests ◽  
Punching Shear ◽  
Deep Foundations ◽  
Layered Soils ◽  
Shape Factors ◽  
Capacity Theory ◽  
Strip Footings

The ultimate bearing capacity of deep foundations has been investigated for the case of a strong layer overlying a weak stratum. The studies are based on model tests using buried circular and strip footings for a range of layer thicknesses. Based on the previously developed bearing capacity theory, the punching shear coefficients and corresponding shape factors have been evaluated.

The Study of Calculation Methods for Foundation Sedimentation

2011 ◽  
Vol 71-78 ◽  
pp. 3229-3232
Author(s):  
Wei He ◽  
Rong He ◽  
Feng Hu
Keyword(s):  
Bearing Capacity ◽  
Calculation Method ◽  
Preventive Measures ◽  
Calculation Methods ◽  
Excessive Pressure ◽  
Foundation Soil ◽  
Type Distribution ◽  
Building Loads

The soil under foundation of building deformed by the top load of which the value depended on not only the size and distribution of building loads, but also the type, distribution, and compression character of foundation soil. If the excessive pressure overloaded the foundation bearing capacity, the foundation would loss stability and breakage. Uneven foundation sedimentation will make the upper building crack. Therefore, the calculation method for foundation sedimentation is very important to guarantee the safety of buildings. In this paper, the calculation theories and methods for foundation sedimentation were compared and the relative preventive measures of disaster were illustrated.

Design Research and Technical Application of the Multi-Type-Pile Composite Foundation

2012 ◽  
Vol 170-173 ◽  
pp. 110-114
Author(s):  
Yan Gao ◽  
Hui Min Li ◽  
Ji Ling Yao
Keyword(s):  
Bearing Capacity ◽  
Design Research ◽  
Composite Foundation ◽  
Social Benefits ◽  
Drilling Machine ◽  
Construction Technology ◽  
Practical Application ◽  
Technical Application ◽  
Foundation Soil ◽  
High Rise

Through project example, analysis of the multi-type-pile composite foundation (lime pile plus CFG pile) in the practical application of liquefied foundation of high-rise building, especially using the ZFZ construction technology which forwards formed a hole and reverses packed into a compaction pile by a long spiral drilling machine to eliminate liquefaction of foundation soil and improve the bearing capacity of foundation is very notable, in addition, it also produces good economic and social benefits, so it has great value of promotion and use.

scholarly journals PENURUNAN OPRIT JEMBATAN SEMARANG LINGKAR UTARA DAN JEMBATAN KALI JAJAR DEMAK JAWA TENGAH DENGAN PRE-FABRICATED VERTICAL DRAIN

2021 ◽  
Vol 4 (1) ◽  
pp. 27
Author(s):  
M Zaki ◽  
Wardani SPR ◽  
Muhrozi Muhrozi
Keyword(s):  
Bearing Capacity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soil Improvement ◽  
Unit Weight ◽  
Fast Time ◽  
Foundation Soil ◽  
Vertical Drain ◽  
Long Time

<p><em>Construction on soft soil, often creates problems. The Semarang North Ring Bridge and Kali Jajar Bridge are the Recent soft Marine Alluvium zones located in the Pantura area which have very soft soil characteristics with a depth of more than -30.0 meters this has resulted in a very large settlement due to very small grains, flood, rob, pore water pressure increases so that the shear strength of the soil will be small, the compression is large and the permeability coefficient is small so that if the construction load exceeds the critical bearing capacity, the damage to the foundation soil will occur. To get the increase in soil bearing capacity, it can be achieved by changing the properties of the soil from the shear angle (</em>f<em>), cohesion (c) and unit weight (</em>g<em>). The settlement can be reduced by increasing the cavity density from the compression of the soil particles (Wesley, 1977). Soil improvement takes a long time, aiming to increase shear resistance so that it requires a fast time in this case is to use Pre-Fabricated Vertical Drain (Bowles 1981). The results of the analysis of the pattern of decline and the effectiveness of the use of PVD (pre-fabricated vertical drain) at the Oprit Bridge in the two research locations have the same decrease in the range of the same heap height at (H = 4 meters) there is a decrease of 117.53 cm at 64 months on the bridge. Kali Jajar (STA. 3 + 200) and there was a decrease of 268.94 cm at 37 months at the Semarang North Ring Bridge</em></p>

scholarly journals INVESTIGATION OF SHALLOW FOUNDATION SOIL BEARING CAPACITY AND SETTLEMENT CHARACTERISTICS OF MINNA CITY CENTRE DEVELOPMENT SITE USING PLAXIS 2D SOFTWARE AND EMPIRICAL FORMULATIONS

2017 ◽  
Vol 36 (3) ◽  
pp. 663-670
Author(s):  
AB Salahudeen ◽  
JA Sadeeq
Keyword(s):  
Soil Properties ◽  
Bearing Capacity ◽  
Average Energy ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Analytical Models ◽  
City Centre ◽  
Foundation Soil ◽  
Development Site ◽  
Allowable Bearing Pressure

This study investigated the soil bearing capacity and foundation settlement characteristics of Minna City Centre development site using standard penetration test (SPT) data obtained from10 SPT boreholes at 0.6, 2.1 and 3.6 m depths to correlate soil properties. Evaluation of foundation bearing capacity and settlement characteristics for geotechnical preliminary design of foundations was carried out using some conventional empirical/analytical models and numerical modelling. The aim was to investigate and determine the geotechnical parameters required for adequate design of Physical structures of the proposed Minna City Centre, at Minna the capital of Niger state. The SPT N-values were corrected to the standard average energy of 60% (N60) before the soil properties were evaluated. Using the corrected N-values, allowable bearing pressure and elastic settlement of shallow foundations were predicted at 50 kN/m2 applied foundation pressure. The numerical analysis results using Plaxis 2D, a finite element code, shows the analytical/empirical methods of estimating the allowable bearing pressure and settlements of shallow foundations that provided acceptable results. Results obtained show that an average bearing capacity value of 100 – 250 kN/m2 can be used for shallow foundations with embedment of 0.6 to 3.6 m on the site.  http://dx.doi.org/10.4314/njt.v36i3.1

scholarly journals Computation of bearing capacity in a multi-layered soil unit: A case study from Dharan, Eastern Nepal

2004 ◽  
Vol 29 ◽  
Author(s):  
Tara Nidhi Bhattarai
Keyword(s):  
Bearing Capacity ◽  
Shear Failure ◽  
Standard Penetration Test ◽  
Layered Soil ◽  
Layer System ◽  
Foundation Soil ◽  
Geological Conditions ◽  
Geotechnical Investigations ◽  
Soil Unit

In this paper, a process of input data preparation for bearing capacity analysis in a multi-layered soil unit is presented. The method first takes into account of the engineering geological conditions of the construction site followed by geotechnical investigations that includes, among others, drilling boreholes at particulars sites also performing standard penetration test (SPT). Besides, various laboratory tests, including consolidation test, were also performed on soil samples collected from different soil layers. Finally, the soil is generalized into certain layer system and the bearing capacity of the foundation soil is computed using both shear failure as well as settlement criteria.

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