scholarly journals Mr Impact Dipping Pyramidal-Prismatic Piles and their Resistance to Pressure and Horizontal Load

2021 ◽  
Author(s):  
Isabai Bekbasarov ◽  
Nurzhan Shanshabayev
Keyword(s):  
Energy Consumption ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Large Scale ◽  
Static Load ◽  
Indentation Load ◽  
Horizontal Load ◽  
Static Loads ◽  
Scale Models ◽  
The Impact

The results of experiments carried out in the field with the use of large-scale models of reinforced concrete driven pyramidal - prismatic piles with different lengths of the pyramidal part are presented. The impact capacity of piles were evaluated of their bearing capacity to the action of indentation and horizontal static loads. It has been established that the driving of pyramidal-prismatic piles is accompanied by both large (by 1.10–1.60 times) and lower (by 8.0–37.0 %) energy consumption for their driving in comparison with conventional pris-matic and pyramidal piles. It was also revealed that under the action of a vertical indentation load, the bearing capacity of the pyramidal-prismatic piles is 1.09–1.48 times, and under the action of a horizontal static load, it is 1.17–1.80 times higher than that of a prismatic pile. It has been established that with an increase in the length of the pyramidal part of the test piles, there is an increase in their bearing capacity by 1.12–1.34 times. Formulas are proposed for determining the bearing capacity of pyramidal-prismatic piles. The research results serve as the basis for the development of recommendations for the calculation and design of pyramidal-prismatic piles.

The Specific Characteristics of Shock and Blast Impacts on Construction Sites

2021 ◽  
pp. 81-88
Author(s):  
A.A. Komarov ◽  
Keyword(s):  
Dynamic Load ◽  
Static Load ◽  
Dynamic Loads ◽  
Potential Hazard ◽  
Construction Sites ◽  
Static Loads ◽  
Equivalent Static Loads ◽  
Plane Crash ◽  
Nuclear Plants ◽  
The Impact

The practices of hazardous and unique facilities’ construction imply that specific attention is paid to the issues of safety. Threats associated with crash impacts caused by moving cars or planes are considered. To ensure safety of these construction sites it is required to know the potential dynamic loads and their destructive capacity. This article considers the methodology of reducing dynamic loads associated with impacts caused by moving collapsing solids and blast loads to equivalent static loads. It is demonstrated that practically used methods of reduction of dynamic loads to static loads are based in schematization only of the positive phase of a dynamic load in a triangle forms are not always correct and true. The historical roots of this approach which is not correct nowadays are shown; such approach considered a detonation explosion as a source of dynamic load, including TNT and even a nuclear weapon. Application of the existing practices of reduction of dynamic load to static load for accidental explosions in the atmosphere that occur in deflagration mode with a significant vacuumization phase may cause crucial distortion of predicted loads for the construction sites. This circumstance may become a matter of specific importance at calculations of potential hazard of impacts and explosions in unique units — for instance, in the nuclear plants. The article considers a situation with a plane crash, the building structure load parameters generated at the impact caused by a plane impact and the following deflagration explosion of fuel vapors are determined.

scholarly journals The impact of secondary ice production on Arctic stratocumulus

2020 ◽  
Vol 20 (3) ◽  
pp. 1301-1316
Author(s):  
Georgia Sotiropoulou ◽  
Sylvia Sullivan ◽  
Julien Savre ◽  
Gary Lloyd ◽  
Thomas Lachlan-Cope ◽  
...  
Keyword(s):  
Large Scale ◽  
Cloud Condensation Nuclei ◽  
The Arctic ◽  
Computationally Efficient ◽  
Eddy Simulation ◽  
Scale Models ◽  
Break Up ◽  
Ice Production ◽  
Low Sensitivity ◽  
The Impact

Abstract. In situ measurements of Arctic clouds frequently show that ice crystal number concentrations (ICNCs) are much higher than the number of available ice-nucleating particles (INPs), suggesting that secondary ice production (SIP) may be active. Here we use a Lagrangian parcel model (LPM) and a large-eddy simulation (LES) to investigate the impact of three SIP mechanisms (rime splintering, break-up from ice–ice collisions and drop shattering) on a summer Arctic stratocumulus case observed during the Aerosol-Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) campaign. Primary ice alone cannot explain the observed ICNCs, and drop shattering is ineffective in the examined conditions. Only the combination of both rime splintering (RS) and collisional break-up (BR) can explain the observed ICNCs, since both of these mechanisms are weak when activated alone. In contrast to RS, BR is currently not represented in large-scale models; however our results indicate that this may also be a critical ice-multiplication mechanism. In general, low sensitivity of the ICNCs to the assumed INP, to the cloud condensation nuclei (CCN) conditions and also to the choice of BR parameterization is found. Finally, we show that a simplified treatment of SIP, using a LPM constrained by a LES and/or observations, provides a realistic yet computationally efficient way to study SIP effects on clouds. This method can eventually serve as a way to parameterize SIP processes in large-scale models.

scholarly journals A Study on the Impact of Nodes Density on the Energy Consumption of LoRa

2021 ◽  
Vol 15 (14) ◽  
pp. 157
Author(s):  
Aizat Faiz Ramli ◽  
Muhammad Ikram Shabry ◽  
Mohd Azlan Abu ◽  
Hafiz Basarudin
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Low Power ◽  
Large Scale ◽  
Sensor Nodes ◽  
Delivery Ratio ◽  
Area Network ◽  
Wide Area Network ◽  
Consumption Ratio ◽  
The Impact

LoRaWAN is one of the leading Low power wide area network (LPWAN) LPWAN technologies that compete for the formation of big scale Internet of Things (IoT). It uses LoRa protocol to achieve long range, low bit rate and low power communication. Large scale LoRaWAN based IoT deployments can consist of battery powered sensor nodes. Therefore, the energy consumption and efficiency of these nodes are crucial factors that can influence the lifetime of the network. However, there is no coherent experimental based research which identifies the factors that influence the LoRa energy efficiency at various nodes density. In this paper, results on measuring the packet delivery ratio, packet loss, data rate and energy consumption ratio ECR to gauge the energy efficiency of LoRa devices at various nodes density are presented. It is shown that the ECR of LoRa is inversely proportional to the nodes density and that the ECR of the network is smaller at higher traffic indicating better network energy efficiency. It is also demonstrated that at high node density, spreading factor SF of 7 and 9 can improve the energy efficiency of the network by 5 and 3 times, respectively, compare to SF 11.

scholarly journals RESEARCH ON THE INFLUENCE OF MILD STEEL DAMPERS ON SEISMIC PERFORMANCE OF SELF-RESETTING PIER

2021 ◽  
Vol 30 (1) ◽  
Author(s):  
Mengqiang Guo ◽  
Yanli Shen
Keyword(s):  
Energy Consumption ◽  
Yield Strength ◽  
Mild Steel ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Seismic Performance ◽  
Compression Ratio ◽  
Axial Compression Ratio ◽  
Steel Damper ◽  
The Impact

In order to improve the energy consumption capacity of the assembled self-resetting pier, the mild steel damper is added to the prefabricated self-resetting pier to form a prefabricated self- resetting pier with an external mild steel damper. Two sets of pier models were established by numerical simulation. On the basis of verifying the correctness of the traditional prefabricated self- resetting pier model, the two sets of pier models were subjected to low-cycle reciprocating loading to study the influence of the mild steel damper yield strength parameters and the pier axial compression ratio parameters on the seismic performance of the pier structure. The results show that compared with traditional prefabricated self-resetting piers, the hysteresis curve of self-resetting piers with mild steel dampers is fuller, and energy consumption and bearing capacity are greatly improved. With the increase of the yield strength of the mild steel damper, the energy consumption capacity will decrease when the loading displacement is less than 25mm, but the overall energy consumption capacity will increase. As the axial compression ratio of the pier column increases, the bearing capacity and energy consumption capacity of the structure increase significantly, but the impact is not obvious when the axial compression ratio exceeds 0.052.

The Impact Sound Insulation of Pre-Loaded Timber Floating Floors on a Concrete Slab

1997 ◽  
Vol 4 (1) ◽  
pp. 39-50
Author(s):  
Michael A. Stewart ◽  
David J. MacKenzie ◽  
Robin K. Mackenzie
Keyword(s):  
Sound Pressure ◽  
Static Load ◽  
Concrete Slab ◽  
Mineral Wool ◽  
Pressure Level ◽  
Sound Insulation ◽  
Additional Increase ◽  
Static Loads ◽  
Significant Difference ◽  
The Impact

When impact sound tests are carried out in new and refurbished flats there is not normally a load on the floor. When the flat is occupied however, loading due to furniture, appliances, people etc, will occur which compresses the resilient layer if a floating floor construction has been used. The effect this has on impact sound insulation is considered in this paper. Impact sound transmission through a chipboard floating floor on battens supported on a concrete floor has been measured when static loads were placed on the chipboard – the loads were in the range 20 kg/m3 to 160 kg/m2. Three different resilient layers under the battens were tested: 25 mm mineral wool quilt, resilient battens and resilient battens on 13 mm mineral wool quilt. The weighted standardised impact sound pressure level (L'nTw) increased by 0.5 dB to 5 dB with the larger increases for the greater loads. Further measurements were made after the floating floors had been left under a static load of 200 kg/m2 for six months: there was an additional increase in L'nTw of 1.5 dB. Finally, measurements were compared with floors where the resilient layers had been soaked to simulate water leakage from baths, pipes etc; there was no significant difference in results.

scholarly journals Analysis of the Impact of Residential Property and Equipment on Building Energy Efficiency and Consumption—A Data Mining Approach

2020 ◽  
Vol 10 (10) ◽  
pp. 3589 ◽  
Author(s):  
Mahsa Nazeriye ◽  
Abdorrahman Haeri ◽  
Francisco Martínez-Álvarez
Keyword(s):  
Data Mining ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Large Scale ◽  
Building Energy Efficiency ◽  
Data Set ◽  
Residential Homes ◽  
Improve Energy Efficiency ◽  
Data Mining Approach ◽  
The Impact

Human living could become very difficult due to a lack of energy. The household sector plays a significant role in energy consumption. Trying to optimize and achieve efficient energy consumption can lead to large-scale energy savings. The aim of this paper is to identify the equipment and property affecting energy efficiency and consumption in residential homes. For this purpose, a hybrid data-mining approach based on K-means algorithms and decision trees is presented. To analyze the approach, data is modeled once using the approach and then without it. A data set of residential homes of England and Wales is arranged in low, medium and high consumption clusters. The C5.0 algorithm is run on each cluster to extract factors affecting energy efficiency. The comparison of the modeling results, and also their accuracy, prove that the approach employed has the ability to extract the findings with greater accuracy and detail than in other cases. The installation of boilers, using cavity walls, and installing insulation could improve energy efficiency. Old homes and the usage of economy 7 electricity have an unfavorable effect on energy efficiency, but the approach shows that each cluster behaved differently in these factors related to energy efficiency and has unique results.

scholarly journals Generalizing Cloud Overlap Treatment to Include Solar Zenith Angle Effects on Cloud Geometry

2007 ◽  
Vol 64 (6) ◽  
pp. 2116-2125 ◽  
Author(s):  
Adrian M. Tompkins ◽  
Francesca Di Giuseppe
Keyword(s):  
Zenith Angle ◽  
Large Scale ◽  
Solar Zenith Angle ◽  
Forecast Model ◽  
Simple Extension ◽  
Scale Models ◽  
Field Geometry ◽  
The Mean ◽  
The Impact ◽  
First Time

Shortwave radiative transfer depends on the cloud field geometry as viewed from the direction of the sun. To date, the radiation schemes of large-scale models only consider a zenith view of the cloud field, and the apparent change in the cloud geometry with decreasing solar zenith angle is neglected. A simple extension to an existing cloud overlap scheme is suggested to account for this for the first time. It is based on the assumption that at low sun angles, the overlap between cloud elements is random for an unscattered photon. Using cloud scenes derived from radar retrievals at two European sites, it is shown that the increase of the apparent cloud cover with a descending sun is reproduced very well with the new scheme. Associated with this, there is a marked reduction in the mean radiative biases averaged across all solar zenith angles with respect to benchmark calculations. The scheme is implemented into the ECMWF global forecast model using imposed sea surface temperatures, and while the impact on the radiative statistics is significant, the feedback on the large-scale dynamics is minimal.

scholarly journals Behavior of fiber-reinforced polymer-strengthened reinforced concrete beams under static and impact loads

2016 ◽  
Vol 8 (1) ◽  
pp. 3-24 ◽  
Author(s):  
Thong M Pham ◽  
Hong Hao
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Impact Loads ◽  
Fiber Reinforced ◽  
Static Loads ◽  
Reinforced Polymer ◽  
Longitudinal Fiber ◽  
The Impact

This study investigates the behavior of fiber-reinforced polymer-strengthened reinforced concrete beams under static and impact loads. The experimental program includes six beams tested in static loads and seven beams tested against impact loads. Longitudinal fiber-reinforced polymer strips and fiber-reinforced polymer U-wraps were used to strengthen these beams. The section of four beams was modified to have a curved soffit in order to reduce the stress concentration of fiber-reinforced polymer U-wraps and provide confinement effect on longitudinal fiber-reinforced polymer strips. The experimental results showed that the proposed modification significantly increased the beam capacities as compared to their rectangular counterparts strengthened with the same amount of fiber-reinforced polymer material. In addition, this article also provides explanations and discussions on the phenomenon of shifting of the flexure failure mode under static loads to the shear–flexure failure mode under impact loads of all the beams tested in the study, as well as the proper interpretations of the measured impact forces in the tests. From the experimental results, it is recommended that the impact force and inertial force at the very early stage of an impact event should be used to design the impact resistance.

scholarly journals NUMERICAL MODELING OF COMPOSITE FITTINGS FOR CLUTCHING WITH CONCRETE

2019 ◽  
Vol 4 (5) ◽  
pp. 56-65 ◽  
Author(s):  
А. Николюкин ◽  
A. Nikolyukin ◽  
В. Ярцев ◽  
Viktor Yarcev ◽  
И. Коломникова ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Numerical Modeling ◽  
Reinforced Concrete ◽  
Numerical Experiment ◽  
Bearing Capacity ◽  
Static Loads ◽  
Reinforcing Bar ◽  
Numerical Studies ◽  
Accumulation Of Defects ◽  
Periodic Profile

Reinforced concrete is one of the most common materials in construction. Constructions made of this material have a high bearing capacity; well perceived dynamic and static loads. This is ensured by the adhesion between the reinforcing bar and concrete. The amount of adhesion is made from a number of different factors formed in the region of the conventional surface of interaction of reinforcement with concrete. It is implied that even if any reinforcement is used, materials come into contact over the surface, which can collapse depending on the load. Violation of the clutch causes significant deformation of the structure, which subsequently leads to a loss of the bearing capacity of the element. Therefore, there is a need to study the magnitude of the adhesion between concrete and reinforcement under various influences. This article describes the results of a numerical experiment on pulling out fiberglass reinforcement of a periodic profile from concrete. A mathematical model is constructed, which allows to study the accumulation of defects and the destruction of reinforcement in the area of concrete fixing. The results of numerical studies are considered.

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