Comportement, en chambre triaxiale, d'un pieu à frottement dans l’argile

1991 ◽  
Vol 28 (3) ◽  
pp. 434-445
Author(s):  
Marius Roy ◽  
Sylvain Roy ◽  
Jean Dubé
Keyword(s):  
Key Words ◽  
Rate Of Penetration ◽  
Pore Pressures ◽  
Model Pile ◽  
Constant Rate ◽  
Order Of Magnitude ◽  
Loading Tests ◽  
Full Scale Tests ◽  
Friction Pile ◽  
Lateral Friction

This study deals with the behaviour of a friction pile in a clay, in a triaxial chamber, and in particular with the generation of pore pressures during driving, and with the mobilization of lateral friction during loading tests at constant rate of penetration and static. The results show that the setting compares with that of a piezocone, and that the pore pressures generated at the point during driving, in the laboratory, are of the same order of magnitude as those obtained on the field. The conditions of reconsolidation used in the laboratory, which define the effective stresses around the pile, allow the calculation of the lateral friction on the model pile. The same conditions of reconsolidation were applied to the full-scale tests, on the Maskinongé site, and yielded values of angles of friction δ of 16° for steel and 20° for concrete. Key words: pile, clay, triaxial chamber, friction, pore pressure. [Journal translation]

Capacité portante de pieux isolés dans les argiles sensibles: étude de cas par la méthode pénétrométrique

1989 ◽  
Vol 26 (3) ◽  
pp. 375-384 ◽  
Author(s):  
Marius Roy ◽  
Luc Tanguay
Keyword(s):  
Bearing Capacity ◽  
Key Words ◽  
Cohesive Soils ◽  
Friction Component ◽  
Good Potential ◽  
Capacité Portante ◽  
Loading Tests ◽  
Single Piles ◽  
Lateral Friction

The penetrometer test has been used to determine the bearing capacity of driven and jacked-in single piles in sensitive clays. The cases presented in this paper were carried out on two sites with steel, concrete, and wooden piles. The bearing capacities calculated on the basis of the results of penetrometer tests show that this approach has a good potential and at the same time is simple and fast. It has been possible to obtain a calibration by a comparison with the loading tests carried out on each of the piles. Taking into account the low strength of some of our clays, experience has to be gained in order to adapt the lateral unit friction curves to our clays. This approach also has the advantage of allowing the determination of the bearing capacity of wooden piles and of taking into account the conical effect when determining the lateral friction component. Key words: penetrometer test, piles, bearing capacity, cohesive soils, point resistance, lateral friction, steel, concrete, wood. [Journal translation]

Effect of loading history on the compression and uplift capacity of driven model piles in sand

1992 ◽  
Vol 29 (2) ◽  
pp. 334-341 ◽  
Author(s):  
R. C. Joshi ◽  
Gopal Achari ◽  
Shenbaga R. Kaniraj
Keyword(s):  
Key Words ◽  
Load Transfer ◽  
Uplift Capacity ◽  
Loading History ◽  
Pile Capacity ◽  
Rate Of Penetration ◽  
Constant Rate ◽  
Tip Resistance ◽  
Tension And Compression ◽  
Load Tests

Model piles were tested in dry uniform sand to study the effect of loading history on the behaviour of piles in compression and tension. A sand bed was prepared by the raining technique, and a smooth cylindrical instrumented pile was driven into the sand. Load tests on piles were conducted at a constant rate of penetration of 0.5 mm/min. The effects of length to diameter (L/D) ratio and sand density were also investigated. The load transfer along the pile surface was studied for an L/D ratio of 33. The pile tip resistance was measured for model piles with L/D ratios of 20–33 and was generally found to be constant. A significant decrease in the pile capacity both in tension and compression was noted for piles having a loading history. When a pile was loaded in compression after being loaded in tension, the tip load could be mobilized only after a certain movement of the pile. The mobilization of the shaft load, however, started immediately. Key words : load tests, model piles, dry sand, loading history, tip capacity, shaft capacity, compression, tension, load transfer.

scholarly journals Pengaruh Waktu Terhadap Daya Dukung Fondasi Tiang Pada Tanah Lunak Dengan Variasi Kekasaran

2020 ◽  
Vol 16 (1) ◽  
pp. 12
Author(s):  
Zoni Satria ◽  
Ferry Fatnanta ◽  
Soewignjo Agus Nugroho
Keyword(s):  
Rate Of Penetration ◽  
Constant Rate

Kapasitas daya dukung tanah lunak sangat kecil, untuk peningkatan daya dukung digunakan fondasi tiang friksi yang menggunakan kekasaran permukaan tiang dengan waktu pemancangan yang telah ditentukan yaitu 0, 4, 8, 16, 32, dan 64 hari. Tujuan penelitian ini adalah Menentukan seberapa besar peningkatan kapasitas daya dukung fondasi tiang dengan variasi kekasaran permukaan tiang dan waktu pengujian pembebanan. Pengujian pembebanan menggunkan metode CRP (Constant Rate of Penetration Method) sedangkan untuk interpretasi kapasitas aksial tiang pancang menggunakan metode Terzaghi dan Peck. Semua variasi waktu akan dianalisis dan dibandingkan hasil daya dukung aksial dari fondasi tiang polos, kekasaran spasi dan kekasaran penuh. Hasil penelitian menunjukan peningkatan daya dukung selalu meningakat dari umur 0 sampai 64 hari. Kapasitas daya dukung fondasi tiang terbesar terdapat pada tiang kekasaran spasi yaitu 55,9 N. tiang kekasaran penuh sebesar 54,5 N dan tiang polos sebesar 22,8 N. Faktor peningkatan daya dukung (∆10) tiang polos sebesar 0,04,  tiang spasi 0,07 dan tiang penuh 0,09 dengan waktu referensi (t0) = 1 hari. Faktor peningkatan (∆10 ) menunjukan faktor peningkatan kapasitas daya dukung tiang seiringnya dengan pertambahan waktu. 

Measurement of Energy Dissipation in a Liquid-Filled, Precessing, Spherical Cavity

1971 ◽  
Vol 38 (3) ◽  
pp. 674-682 ◽  
Author(s):  
J. P. Vanyo ◽  
P. W. Likins
Keyword(s):  
Energy Dissipation ◽  
Spherical Cavity ◽  
Mechanical Energy ◽  
Rigid Sphere ◽  
Analytical Approximations ◽  
Constant Rate ◽  
Experimental Apparatus ◽  
Half Angle ◽  
Analytical Estimation ◽  
Order Of Magnitude

Methods are described for the experimental measurement and analytical estimation of the losses of mechanical energy in a spinning and precessing spherical cavity filled with fluid. Test results are presented and correlated with analytical estimates based on two different mathematical models of the system. The experimental apparatus is a gimbaled mechanism which constrains a rigid body with a spherical cavity to spin about an axis through the cavity center at a constant rate ψ˙, while the spin axis cones about an inertially fixed axis at a constant rate φ˙ with a constant conical half angle θ. Measurements of current required by motors which maintain the constancy of ψ˙ and φ˙ provide a measure of the energy losses in the fluid in the steady state, after suitable dry test calibrations. Experimental results are presented for a 22-cm-dia cavity containing fluids of kinematic viscosities of 1 and 20 centistokes, with θ ranging from 5–30 deg, ψ˙ ranging from 60–1000 rpm, and φ˙ ranging from −400 to +600 rpm. Analytical approximations are developed on the basis of (a) a variation of the oscillating flat-plate solution, and (b) a rigid interior sphere of fluid idealization. The rigid sphere method gives energy dissipation rates that are generally valid over most of the important range of parameters, while the oscillating surface solution is generally an order of magnitude too low in its predictions of energy dissipation.

Mechanical Mechanism of the Post-Grouting Pile

2013 ◽  
Vol 351-352 ◽  
pp. 510-514
Author(s):  
Bin Wang ◽  
Jie Zhang
Keyword(s):  
Finite Element ◽  
Field Test ◽  
Axial Force ◽  
Simulation Data ◽  
Performance Simulation ◽  
Finite Element Software ◽  
Bored Piles ◽  
Post Grouting ◽  
Friction Pile ◽  
Lateral Friction

The bored piles are widely used in engineering, but also a lack of understanding of the mechanical mechanism of post-grouting technology, design and calculations based on the experience. Using FLAC3D finite element software, analyzing from axial force, pile lateral friction, pile end resistance to improve the carrying performance. Simulation data and field test QS curves is almost consistent, verifying that the model is correct. Contrasting between the not-grouting pile and grouting pile, finding that the limit lateral friction and end resistance of grouting pile have significantly increased in the maximum loads.

Study on the Bearing Capacity of Slime Friction Pile Based on the Double-Sheared Theory

2013 ◽  
Vol 353-356 ◽  
pp. 1005-1010
Author(s):  
Xiang Qiu Wang ◽  
Wen Tao Yang
Keyword(s):  
Bearing Capacity ◽  
Strength Criterion ◽  
Intermediate Principal Stress ◽  
Resistance Force ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Friction Resistance ◽  
Double Shear ◽  
Friction Pile ◽  
Lateral Friction

The bearing capacity of slime friction pile based on the Mohr-Coulombs strength criterion couldnt make full use of the potential strengths ability of rock-soil. But the double shear unified strength theory can depict really the bearing characteristics of rock-soil because it can consider the effect of intermediate principal stress comprehensively. On this condition, based on the Mindlins displacement solution and the double shear unified strength theory, a calculated formula of bearing capacity was proposed for the slime friction pile, and then the distribution regularities of lateral friction-resistance force for the slime friction pile were discussed.

Density Estimates of Mysis relicta in Lake Michigan

1979 ◽  
Vol 36 (6) ◽  
pp. 694-698 ◽  
Author(s):  
Nevin E. Grossnickle ◽  
Mark D. Morgan
Keyword(s):  
Key Words ◽  
Lake Michigan ◽  
Density Estimates ◽  
Mysis Relicta ◽  
Deep Station ◽  
Late Instar ◽  
Order Of Magnitude

Density estimates of Mysis relicta based on night vertical net tows at stations of 30–50 m in Lake Michigan were about an order of magnitude larger than previous estimates based on sled tows. Significantly greater density estimates were obtained in night vertical net tows than those collected before sunset at these shallow stations. However, density estimates based on sled tows during daylight were not significantly different from those based on night vertical net tows at a 115-m station in Lake Michigan. At this deep station, a substantially larger percentage of late instar mysids was collected in sled tows than in night vertical net tows. Key words: Mysis relicta, Lake Michigan, density estimates, vertical net tows, epibenthic sled tows

Tassement et consolidation au dégel d'un silt argileux à Kangiqsualujjuaq

1991 ◽  
Vol 28 (5) ◽  
pp. 678-689
Author(s):  
Serge Leroueil ◽  
Guy Dionne ◽  
Michel Allard
Keyword(s):  
Key Words ◽  
Physical Characteristics ◽  
Pore Pressures ◽  
Clayey Silt ◽  
Excess Pore Pressures ◽  
Excess Pore

The physical characteristics, the compressibility, and the consolidation of a permafrost clayey silt of Kangiqsualujjuaq, Quebec, have been studied, in the laboratory and in the field, by melting the permafrost in the foundation of an excavation. It appears that the values of the thawing settlement parameter (A0) obtained in the laboratory and in the field coincide perfectly with one another, and with those found in the literature for the same type of soil. It has also been observed, on that site, that the thawing of the permafrost, even though ice-rich, does not generate excess pore pressures. Key words: permafrost, compressibility, consolidation, laboratory, in situ. [Journal translation]

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