Effect of anisotropy on drained and undrained shear behavior of in-situ sandy soils

Author(s):  
Akihiko Uchida ◽  
Yuji Taya ◽  
Munenori Hatanaka
1970 ◽  
Vol 7 (4) ◽  
pp. 482-493 ◽  
Author(s):  
V. A. Sowa

The pulling capacity of cylindrical concrete piles cast in situ in bored holes is examined for piles constructed in sandy or cohesive soils. On the basis of the data presented, it is concluded that the pulling capacity of these piles in cohesive soils can be estimated approximately, while the pulling capacity of piles in sandy soil is considerably more difficult to estimate. Estimating the pulling capacity of piles in cohesive soils is based on an empirical relationship between soil adhesion and the undrained shear strength. A possible explanation for the difficulty in estimating the pulling capacity of piles in sandy soils is suggested.


2012 ◽  
Vol 11 (12) ◽  
pp. 2163-2168
Author(s):  
Alexandra-Dana Chitimus ◽  
Valentin Nedeff ◽  
Emilian Florin Mosnegutu ◽  
Mirela Panainte

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2313
Author(s):  
Maria Luisa Beconcini ◽  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi ◽  
Benedetta Puccini

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.


Land ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 503
Author(s):  
Heleen Vos ◽  
Wolfgang Fister ◽  
Frank Eckardt ◽  
Anthony Palmer ◽  
Nikolaus Kuhn

The sandy croplands in the Free State have been identified as one of the main dust sources in South Africa. The aim of this study was to investigate the occurrence and strength of physical soil crusts on cropland soils in the Free State, to identify the rainfall required to form a stable crust, and to test their impact on dust emissions. Crust strength was measured using a fall cone penetrometer and a torvane, while laboratory rainfall simulations were used to form experimental crusts. Dust emissions were measured with a Portable In-Situ Wind Erosion Laboratory (PI-SWERL). The laboratory rainfall simulations showed that stable crusts could be formed by 15 mm of rainfall. The PI-SWERL experiments illustrated that the PM10 emission flux of such crusts is between 0.14% and 0.26% of that of a non-crusted Luvisol and Arenosol, respectively. The presence of abraders on the crust can increase the emissions up to 4% and 8% of the non-crusted dust flux. Overall, our study shows that crusts in the field are potentially strong enough to protect the soil surfaces against wind erosion during a phase of the cropping cycle when the soil surface is not protected by plants.


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