scholarly journals Geotechnical characterization and modelling of the “Fallen Lands” phenomenon in the amazon environment

2021 ◽  
Vol 9 (3) ◽  
pp. 122-132
Author(s):  
Elias Santos Souza ◽  
Nilton de Souza Campelo ◽  
Raimundo Humberto Cavalcante Lima ◽  
René Levy Aguiar
Keyword(s):  
Shear Strength ◽  
Computational Models ◽  
Sandy Soils ◽  
Shear Resistance ◽  
Critical Conditions ◽  
Soil Layers ◽  
Economic Problems ◽  
Geotechnical Characterization ◽  
Scale Models ◽  
Reduced Scale

In many rivers of the Amazon, mainly along the Amazon River, the phenomenon of "fallen land" occurs at the time of the rivers' ebb, causing the erosion of river banks, resulting in major social and economic problems. The influence of saturation/percolation of soil layers on the shear resistance of the affected massifs is unknown. Thus, the main objective of the characterization and geotechnical modelling of these slopes is to determine the shear strength of the affected massifs. For this purpose, deformed and undeformed samples were collected from the various layers of the soil massif in a location where the phenomenon was under development. These samples were characterized physically, chemically, and mechanically. Subsequently, the massifs were recreated in reduced scale models, observing the critical conditions in which the disaster occurred, and qualitatively comparing them with slope stability computational models. The results showed that the layers are classified as silty and sandy soils, with a small fraction of clay, and that there are three types of movements associated with the fallen soils: the fall, overturning, and rotational landslide, all actively influenced by the effects of the river's ebb, saturation/percolation, and texture.

Shaking Table Test Analysis of Bottom-Business Multi-Story Masonry Structure in Small and Middle Towns in the Southward

2014 ◽  
Vol 580-583 ◽  
pp. 1463-1466
Author(s):  
Yong Duo Liang ◽  
Xun Guo ◽  
Hua Wei Yi ◽  
Yong Zhen Li ◽  
Jin Zheng Jiang
Keyword(s):  
Shaking Table Test ◽  
Masonry Structure ◽  
Shaking Table ◽  
Earthquake Simulation ◽  
Seismic Capacity ◽  
Test Analysis ◽  
Earthquake Resistant ◽  
Scale Models ◽  
Longitudinal Wall ◽  
Reduced Scale

Bottom-business multi-story masonry structure is widely used in small and middle towns in the southward in China. In the downtown of Beichuan county which affected by Wenchuan earthquake, more than 80% of this kind of building collapsed. But the Apartment of Beichuan Telecommunication Bureau behaved well earthquake resistant capacity with a moderate damage in the earthquake. The obvious difference between this building and others is the setting of winged columns in the front longitudinal wall of the first floor. For proving the influence of these members in the structure seismic capacity, the earthquake simulation shaking table test of 2 1/5 reduced scale models were designed and carried out. The models dynamic response, acceleration, displacement and strain were measured and collected, that model with winged columns behave well was testified. And the reinforcement method of balancing stiffness and increasing ductility is put forward. The results provide a foundation for the retrofitting design of the existing houses.

scholarly journals Influence of coarse aggregate on shear resistance of self-consolidating concrete beams

2017 ◽  
Vol 10 (1) ◽  
pp. 30-40
Author(s):  
G. SAVARIS ◽  
R. C. A. PINTO
Keyword(s):  
Shear Strength ◽  
Failure Modes ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Self Consolidating Concrete ◽  
Coarse Aggregates ◽  
Lower Shear ◽  
Nominal Size ◽  
High Flowability

Abstract Self-consolidating concrete is characterized by its high flowability, which can be achieved with the addition of superplasticizer and the reduction of the amount and size of coarse aggregates in the concrete mix. This high flowability allows the concrete to properly fill the formwork without any mechanical vibration. The reduction in volume and particle size of the coarse aggregates may result in lower shear strength of beams due to a reduced aggregate interlock. Therefore, an experimental investigation was conducted to evaluate the influence of the reduction in the volume fraction and the nominal size of coarse aggregate on concrete shear strength of self-consolidating beams. Six concrete mixes were produced, four self-consolidating and two conventionally vibrated. A total of 18 beams, with flexural reinforcement but without shear reinforcement were cast. These beams were tested under a four-point loading condition. Their failure modes, cracking patterns and shear resistances were evaluated. The obtained shear resistances were compared to the theoretical values given by the ACI-318 and EC-2 codes. The results demonstrated a lower shear resistance of self-consolidating concrete beams, caused mainly due to the reduced aggregate size.

scholarly journals Lateral shear strength of rectangular RC columns subjected to combined P-V-M monotonic loading

2020 ◽  
Vol 53 (4) ◽  
pp. 227-241
Author(s):  
Aysha M Zaneeb ◽  
Rupen Goswami ◽  
C V R Murty
Keyword(s):  
Shear Strength ◽  
Test Data ◽  
Rectangular Cross Section ◽  
Resistance Mechanism ◽  
Bending Moment ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Longitudinal Reinforcement ◽  
Lateral Shear ◽  
Rc Columns

An analytical method is presented to estimate lateral shear strength (and identify likely mode and location of failure) in reinforced concrete (RC) cantilever columns of rectangular cross-section under combined axial force, shear force and bending moment. Change in shear capacity of concrete with flexural demand at a section is captured explicitly and the shear resistance offered by concrete estimated; this is combined with shear resistance offered by transverse and longitudinal reinforcement bars to estimate the overall shear capacity of RC columns. Shear–moment (V-M) interaction capacity diagram of an RC column, viewed alongside the demand diagram, identifies the lateral shear strength and failure mode. These analytical estimates compare well with test data of 107 RC columns published in literature; the test data corresponds to different axial loads, transverse reinforcement ratios, longitudinal reinforcement ratios, shear span to depth ratios, and loading conditions. Also, the analytical estimates are compared with those obtained using other analytical methods reported in literature; in all cases, the proposed method gives reasonable accuracy when estimating shear capacity of RC columns.  In addition, the method provides insights into the shear resistance mechanism in RC columns under the combined action of P-V-M, and it is simple to use.

Shear and flexural behaviour of lightweight self-consolidating concrete beams

2021 ◽  
Author(s):  
Kokilan Sathiyamoorthy
Keyword(s):  
Shear Strength ◽  
Crack Width ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Normal Weight ◽  
Shear Behaviour ◽  
Flexural Behaviour ◽  
Self Consolidating Concrete ◽  
Shear Span ◽  
Flexural Performance

Shear and flexural behaviour of lightweight self-consolidating concrete (LWSCC) beams made of slag aggregates were investigated. Shear reinforced LWSCC beams showed similar shear behaviour compared to their non-shear reinforced counterparts until the formation of diagonal cracks but higher ultimate shear resistance and ductility. Compared to normal weight self-consolidating concrete (SCC) ones, non-shear reinforced LWSCC beams showed lower post-cracking shear resistance. Shear strength of LWSCC/SCC beams increased with the decrease of shear span to depth ratio. LWSCC beams showed higher number of cracks and wider crack width at failure than their SCC counterparts. LWSCC beams developed higher number of cracks with wider crack width at failure compared with their SCC counterparts. American, Canadian and British Codes were conservative in predicting shear strength of shear/non-shear reinforced LWSCC beams. LWSCC beams (with slag aggregate) showed good shear resistance compared with those made of other types of aggregates besides satisfactory flexural performance.

Investigation of the Mechanical Behavior of 3D Printed Polyamide-12 Joints for Reduced Scale Models of Rock Mass

2020 ◽  
Vol 53 (6) ◽  
pp. 2687-2705
Author(s):  
Jana Jaber ◽  
Marianne Conin ◽  
Olivier Deck ◽  
Mohamed Moumni ◽  
Olivier Godard ◽  
...  
Keyword(s):  
Rock Mass ◽  
Mechanical Behavior ◽  
Polyamide 12 ◽  
Scale Models ◽  
3D Printed ◽  
Reduced Scale

scholarly journals Experimental investigation on shear properties of warp-knitted brush fabrics

2020 ◽  
Vol 15 ◽  
pp. 155892502094645
Author(s):  
Yao Chu ◽  
Haitao Lin ◽  
Hafsa Jamshaid ◽  
Qi Zhang ◽  
Pibo Ma
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Outer Surface ◽  
Shear Force ◽  
Shear Resistance ◽  
Experimental Results ◽  
Shear Properties ◽  
Factors Affecting ◽  
Car Seat ◽  
Seat Cushions

Warp-knitted brush fabrics are composed of an outer surface formed by weaving the front and rear needle beds with spacer yarns interposed between them. Warp-knitted brush fabrics can be used as a non-slip cover for car seat cushions; the adhesion between non-slip fabric and car seat is related to the shear strength of warp-knitted brush fabrics. In this article, to study the factors affecting the shear force of warp-knitted brush fabrics, three different processing methods and four different stretching speed intervals were used to find the effects of stiffeners and action of different speed intervals on shear properties of fabrics. The experimental results show that the stiffener treatment can improve the shear resistance of the warp-knitted brush fabrics, and the effect of different speed intervals can affect the shear resistance of fabrics. These findings will have a guiding significance in the design and production of warp-knitted brush fabrics applied to fabrics such as car seat cushions, and the results can also help to study the shear properties of warp-knitted brush fabrics for wider applications.

scholarly journals Acrylic Pressure-Sensitive Adhesives Containing SiO2 Nanoparticles

2013 ◽  
Vol 15 (1) ◽  
pp. 12-14 ◽  
Author(s):  
Zbigniew Czech ◽  
Agnieszka Kowalczyk ◽  
Joanna Ortyl ◽  
Jolanta Świderska
Keyword(s):  
Shear Strength ◽  
Sio2 Nanoparticles ◽  
Shear Resistance ◽  
Inorganic Filler ◽  
Pressure Sensitive Adhesives ◽  
Medical Products ◽  
Pressure Sensitive ◽  
Protective Films ◽  
Carrier Free ◽  
Peel Adhesion

The use of acrylic pressure-sensitive adhesives (PSAs) is increasing in a variety of industrial fields. They have been applied in the manufacture of mounting tapes, self-adhesive labels, protective films, masking tapes, splicing tapes, carrier-free tapes, sign and marking films, and in diverse medical products, such as pads or self-adhesive bioelectrodes. In this study, the application of SiO2 nanoparticles in acrylic PSA was investigated. The properties of the newly synthesized and modified PSA were evaluated via the tack, peel adhesion, shear-strength and shrinkage. It has been found that the nanotechnologically-reinforced systems consisting of monodisperse non-agglomerated SiO2 nanoparticles and self-crosslinked acrylic PSAs showed a great enhancement in tack, peel adhesion, shear resistance and shrinkage, without showing the disadvantages known to result from the use of other inorganic additives. In this paper we evaluate the performance of SiO2 nanoparticles with a size of about 30 nm as inorganic filler into the synthesized solvent-borne acrylic PSA.

Influence of Stirrup Corrosion on Shear Strength of RC Beams

2012 ◽  
Vol 204-208 ◽  
pp. 3287-3293
Author(s):  
Xin Xue ◽  
Hiroshi Seki ◽  
Yu Song
Keyword(s):  
Shear Strength ◽  
Mass Loss ◽  
Local Maximum ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Maximum Mass ◽  
Rc Beams ◽  
Load Carrying ◽  
Maximum Mass Loss

There have been few reports on shear behavior of reinforced concrete (RC) beams with corroded stirrups, and the influence of stirrup corrosion has yet to be identified. Given this background, experience was carried out to investigate the shear behavior of RC beams containing corroded stirrups. Investigation results indicate that if the percentage local maximum mass loss is below 35%, there is little influence on the load-carrying mechanism. The concrete shear resistance seems to change little and the shear capacity can be calculated by just taking into consideration the reduction in stirrup shear resistance. It is also found that the anchorage conditions of the stirrups have a predominant influence on the shears of RC beams.

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