Pullout capacity of slab anchors in sand

1989 ◽  
Vol 26 (3) ◽  
pp. 385-400 ◽  
Author(s):  
S. Frydman ◽  
I. Shaham

The pullout capacity of slab anchors in homogeneous sand depends on several factors including the type and density of the sand, and the depth, size, inclination, and shape of the slab. Although numerous publications have reported results of pullout tests on small models and prototypes, the investigations described have generally been limited to a study of the effects of one or two of the above factors, and no attempt has been made to develop an integrated approach to the problem. This paper presents such an approach by reanalyzing the results of published experimental data as well as those of a series of pullout tests performed on prototype slabs placed at various inclinations and depths in a dense sand profile. A simple theoretical expression is found to reasonably predict the pullout capacity of a continuous, horizontal slab as a function of depth-to-width ratio. Factors to account for shape, and inclination, are then established leading to expressions for the estimation of pullout capacity of any slab anchor. Key words: anchors, field tests, model tests, pullout capacity, sand, slabs, plates.

Volume 2 ◽  
2004 ◽  
Author(s):  
Renzo Capitani ◽  
Tommaso Iacomelli ◽  
Daniele G. Rosti ◽  
Pierluigi Tozzi

The Universita` degli Studi di Firenze joined the Formula Student competition (organised by SAE and IMechE) in 2002 competing in Class 3, the following year the first car was ready to compete in Class 1. In order to build this car, an integrated approach was adopted to obtain the best solution in every aspect. The purpose of the design was to optimise the car handling, fulfilling the Formula SAE rules. All the design phases were based on the Design for X approach, with the aim to optimise all the aspects of the Formula SAE project, like performance, design and cost. A Design for Manufacturing approach was added to the FEA to design all the components, like uprights and wheel spindles, in order to simplify the CNC machining. The suspensions layout was defined using a recursive method based on the Multibody Simulation and the components design. Some experimentations were conducted to verify the simulations. The experimental data were used to start the redesign, to improve the performance of the new car that will compete in the 2004 events.


2010 ◽  
Vol 47 (4) ◽  
pp. 400-412 ◽  
Author(s):  
Dariusz Wanatowski ◽  
Jian Chu ◽  
Wai Lay Loke

Flowslide or failure of loose granular soil slopes is often explained using liquefaction or instability data obtained from undrained triaxial tests. However, under static loading conditions, the assumption of an undrained condition is not realistic for sand, particularly clean sand. Case studies have indicated that instability of granular soil can occur under essentially drained conditions (e.g., the Wachusett Dam failure in 1907). Laboratory studies on Changi sand by Chu et al. in 2003 have shown that sand can become unstable under completely drained conditions. However, these studies were carried out under axisymmetric conditions and thus, cannot be applied directly to the analysis of slope failures. In this paper, experimental data obtained from plane-strain tests are presented to study the instability behaviour of loose and dense sand under plane-strain conditions. Based on these test data, the conditions for the occurrence of drained instability in plane strain are established. Using the modified state parameter, the conditions for instability under both axisymmetric and plane-strain conditions can be unified. A framework for interpreting the instability conditions of sandy slopes developed under axisymmetric conditions also extends into plane-strain conditions.


1989 ◽  
Vol 69 (3) ◽  
pp. 711-714 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY

The half-life of metribuzin applied to a bare soil surface was calculated to be 3–7 d over four field tests. An artificial cover erected after application or a shallow incorporation increased the half-life of metribuzin approximately 2.5- to 3-fold. Leaching out of the 0- to 5-cm-deep sampling zone could not account for loss of metribuzin. It was concluded that metribuzin persistence may be affected by volatility and/or photodecomposition losses under field conditions, especially shortly after application. Key words: Metribuzin half-life, volatility, photodecomposition, row width


2010 ◽  
Vol 46 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y. Du ◽  
J. Wang ◽  
Y.F. Ouyang ◽  
L.J. Zhang ◽  
Z.H. Yuan ◽  
...  

An integrated approach of experiment and theoretical computation to acquire enthalpies of formation for ternary compounds is described. The enthalpies of formation (DHf ) for Al71Fe19Si10 and Al31Mn6Ni2 are measured via a calorimeter. Miedema model, CALPHAD and first-principles method are employed to calculate DHf for the above compounds and several Al-based ternary compounds. It is found that first-principles generated data yield good agreements with experimental values and thus can be used as key 'experimental data', which are needed for CALPHAD approach.


2021 ◽  
Vol 318 ◽  
pp. 01010
Author(s):  
Mais S. Al-Tememy ◽  
Mohammed A. Al-Neami ◽  
Mohammed F. Asswad

Batter or raker piles are piles driven at an inclination with a vertical to resist large inclined or lateral forces. Many structures like offshore structures and towers are subjected to overturning moments due to wave pressure, wind load, and ship impacts. Therefore in such structures, a combination of the vertical and batter piles is used to transfer overturning moments in compression and tension forces to the foundation. This paper presents a three-dimensional finite element analysis using PLAXIS 3D software to study the battered pile's behavior under the effect of pullout load. Several variables that influence the pile tension capacity embedded in sandy soil are investigated. The pile models are steel piles embedded in the dense sand at different batter angles (0, 10, 20, and 30) degrees with two embedment ratios, L/d (15 and 20). To clarify the pile shape's influence on a pullout capacity, two shapes are used, a circular pile with a diameter equal to 20 mm and a square pile with a section of 15.7×15.7 mm. These dimensions are chosen to achieve an equal perimeter for both shapes. The numerical results pointed that the pile pullout capacity increases with the increasing of the batter angle and embedment ratio, and the maximum values are marked at a batter angle of 20o. The shape of the bending moment profile is a single curvature, and the peak values are located approximately at the midpoint of the battered pile, while a zero value is located at the pile tip and pile head.


2021 ◽  
Vol 27 (12) ◽  
pp. 1-12
Author(s):  
Haider N. Abdul Hussein ◽  
Qassun S. Mohammed Shafiqu ◽  
Zeyad S. M. Khaled

Experimental model was done for pile model of L / D = 25 installed into a laminar shear box contains different saturation soil densities (loose and dense sand) to evaluate the variation of pore water pressure before and after apply seismic loading. Two pore water pressure transducers placed at position near the middle and bottom of pile model to evaluate the pore water pressure during pullout tests. Seismic loading applied by uniaxial shaking table device, while the pullout tests were conducted through pullout device. The results of changing pore water pressure showed that the variation of pore water pressure near the bottom of pile is more than variation near the middle of pile in all tests. The variation of pore water pressure after apply seismic loading is more than the variation before apply seismic loading near the middle of pile and near the bottom of pile and in loose and dense sand. Variation of pore water pressure after apply seismic loading and uplift force is less than the variation after apply seismic loading in loose sand at middle and bottom of pile.


Author(s):  
Zinovii Pankiv

The structure of soils in Carpathian region of Ukraine, which is involved for agricultural land use, including for arable land, has been analyzed. The basic steps to increase the area of arable land have been described. Integrated approach with using spatial, legal, environmental, and economic performance has been proposed for definition of the efficiency of agricultural land use. The appellation “soil use” for characteristic the type using of agricultural land resources has been proposed. Key words: productive soils, land use, the Carpathian region of Ukraine, soil use


1998 ◽  
Vol 76 (10) ◽  
pp. 1457-1466 ◽  
Author(s):  
Luigi Cavallo ◽  
Tom K Woo ◽  
Tom Ziegler

A combined density functional and molecular mechanics approach (QM/MM) has been validated in a study of the substitution reactions: (i) (PH3)2Fe(CO)3 + 2ER3 ⇆ (ER3)2Fe(CO)3 + 2PH3(ER3 = PMe3, PEt3, PMePh2, PPh3, PCyPh2, PiPr3, PBz3, PCy3, AsEt3, AsPh3); and (ii) Cp'Ru(PH3)2Cl + 2ER3 ⇆ Cp'Ru(ER3)2Cl + 2PH3 (Cp' = C5H5, C5(CH3)5; ER3 = PMe3, PEt3, PnBu3, PMe2Ph, PMePh2, PPh3, AsEt3, P(OMe)3, P(OPh)3, P(OCH2)3CEt). The steric influence of the R substituents on the substitution enthalpies correlates well with experimental data. The combined QM/MM approach is also able to afford molecular structures in good accord with experimental estimates. Key words: combined QM/MM, ligand substitutions, organometallic complexes.


2012 ◽  
Vol 226-228 ◽  
pp. 1304-1307
Author(s):  
Jason Y. Wu ◽  
Jr Min Chang

In this research, laboratory pullout tests were conducted on grouted soil nails to study the effect of wetting on the interface shear resistance between nail and soil during pullout. Deformed bars with equal size to the true soil nails were used as model nails. The soil used was silty fine sand collected at the site and prepared to a very dense condition. Rainfall infiltration was simulated using duplicated soil nails inundated by water for different periods. Test results indicated that the peak pullout resistance strongly decreases upon wetting, with a reduction of about 60% after soaking for 28 days. However, the experiments showed that there is a threshold water content (or soaking time) beyond which the effect of infiltration on the pullout resistance is reduced. The laboratory protocols developed in this study offered an easy scheme for the prediction of the pullout capacity of a grouted soil nail upon wetting.


1989 ◽  
Vol 16 (3) ◽  
pp. 384-399 ◽  
Author(s):  
Darrel P. Gagnon ◽  
D. J. Laurie Kennedy

Partial joint penetration groove welds may be used in columns, for example, when it is not necessary to develop the full tensile capacity of the cross section. Also, where it is not feasible to make a full joint penetration groove weld because welding can be done from one side only, the strength of a partial joint penetration groove weld may be adequate. Limited experimental data have shown that the strength of partial penetration welds are proportional to their areas.A series of 75 tests on 25 mm thick, grade 300W and grade 350A steel plates, with welds made with matching electrodes and with 20–100% penetration, were conducted. The overall behaviour, the effects of percent penetration, plate strength, and the eccentricity of the load were investigated. The inherent ductility of the welds allows lateral deflections and straining to take place so that eccentrically loaded welds are as strong as concentrically loaded welds. The strength of welds is greater than the strength of the plate multiplied by the percent penetration and increases with the increasing lateral restraint that occurs with decreasing penetration. Design equations and resistance factors, based on weld strengths at least equal to the percent penetration multiplied by the ultimate tensile resistance of the plate, are proposed. Recommendations for fabrication are presented. Key words: behaviour, groove weld, limit states, partial joint penetration, strength, resistance factor, tension, ultimate.


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