scholarly journals An Optimized Prefabricated Raft Footing System for Houses on Shrink-Swell Soils: Preliminary Results

2019 ◽  
pp. 59-66 ◽  
Author(s):  
Bertrand Teodosio ◽  
Kasun Shanaka ◽  
Kristombu Baduge ◽  
Priyan Mendis
Keyword(s):  
Soil Moisture ◽  
Structural Integrity ◽  
Skilled Labor ◽  
Manual Labor ◽  
Light Weight ◽  
Severe Damage ◽  
Construction Period ◽  
Ground Movements ◽  
Prefabricated Houses ◽  
Site Disturbance

The strong demand for houses has been hampered by a shortage of skilled labor in Australia, which can be potentially alleviated using prefabrication. Significant advancements in the design and construction of prefabricated houses have been observed; however, most substructure constructions still use traditional cast-in-place method that is labor intensive and weather-dependent. Prefabrication of footing systems is an advantageous solution since this require minimal manual labor and shorter construction period. The design of an innovative prefabricated footing needs to consider structural integrity and design assembly. One of the important structural issues for light-weight houses is cyclic differential ground movements affecting footing systems due to reactive soils. This shrink-swell movements are due to the decrease and increase in soil moisture, which can cause minor to severe damage depending on the presence of fines. Due to the issues on shortage of skilled labor and housing, and the costly impact of shrink-swell movements of reactive soils to footings, this study aims to develop a prefabricated footing based on optimized waffle raft. The developed system can easily be installed in stable to highly reactive sites, minimizing site disturbance, on-site assembly requirements and maximizing construction speed, quality and sustainability.

Sloshing Characteristics of Single Deck Floating Roofs in Aboveground Storage Tanks: Natural Periods and Vibration Modes

2009 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
Katsuki Iwata
Keyword(s):  
Structural Integrity ◽  
Oil Refining ◽  
Vibration Modes ◽  
Storage Tanks ◽  
Severe Damage ◽  
Element Analysis ◽  
Linear Elastic ◽  
Oil Storage ◽  
Hydrodynamic Coupling ◽  
Roof Design

The floating roofs are widely used to prevent evaporation of content in large oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to the floating roofs due to liquid sloshing. The structural integrity of the floating roofs for the sloshing is urgent issue to establish in the petrochemical and oil refining industries. This paper presents the sloshing characteristics of the single deck floating roofs in cylindrical storage tanks. The hydrodynamic coupling of fluid and floating roof is taken into consideration in the axisymmetric finite element analysis. It is assumed that the fluid is incompressible and inviscid, and the floating roof is linear elastic while the sidewall and the bottom are rigid. The basic vibration characteristics, natural periods and vibration modes, of the floating roof due to the sloshing are investigated. These will give engineers important information on the floating roof design.

scholarly journals IDENTIFIKASI CENDAWAN YANG BERPOTENSI MENYEBABKAN PENYAKIT BUSUK KUNING PADA BATANG TANAMAN BUAH NAGA

2019 ◽  
Vol 4 (1) ◽  
pp. 1-6
Author(s):  
Nova Kurniasari ◽  
Nur Annis Hidayati ◽  
Tri Wahyuni
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Research Method ◽  
Pathogenic Fungi ◽  
Air Humidity ◽  
Severe Damage ◽  
Microscopic Identification ◽  
Dragon Fruit ◽  
Fruit Plants

The attack of pathogenic fungi on dragon fruit plants in Penyak Village causes severe damage and shows symptoms of yellow rot on the trunk of dragon fruit. The research method used is exploration and identification. This study aims to explore fungi that have the potential to cause yellow rot based on the symptoms of yellow rot on the stems of dragon fruit plants in Penyak Village, Koba District, Central Bangka Regency. The results of 16 stem samples obtained 64 isolates and based on macroscopic and microscopic identification results of each isolate obtained seven genera namely Acremonium, Alternaria, Aspergillus, Cladosporium, Geotrichum, Fusarium, and Pestalotiopsis. The most common pathogenic fungi at mild symptoms are Pestalotiopsis, Alternaria, and Fusarium. Environmental factors (abiotic) such as soil moisture and air humidity that are high enough to affect the genus present, especially Fusarium.

scholarly journals Research and Application Status of Envelope Structures for Fabricated Substations in China

2020 ◽  
Vol 189 ◽  
pp. 03037
Author(s):  
Xueqing Sheng ◽  
Shengjun Pan ◽  
Jiahui Chen
Keyword(s):  
Rapid Growth ◽  
Manual Labor ◽  
Chinese Market ◽  
Wet Work ◽  
Construction Period ◽  
Building Systems ◽  
Wall Panels ◽  
Selection Of ◽  
Prefabricated Building

In recent years, Chinese prefabricated buildings have re-heated and showed rapid growth. This paper analyzes the performance of the existing assembled wall panels in the Chinese market by comparing the performance of different materials and optimizing the selection of the envelope structure of the assembled substation. Studies have shown that the use of prefabricated building systems can achieve the goal of shortening the construction period, reducing manual labor, no waste during construction, and no wet work on site.

Dynamic Characteristic Analysis of Prefabricated Houses of Light-Weight Steel Structure

2014 ◽  
Vol 578-579 ◽  
pp. 483-487 ◽  
Author(s):  
Hui Min Xu ◽  
Yang Yang Li ◽  
Wei Xu
Keyword(s):  
Dynamic Characteristic ◽  
Natural Frequencies ◽  
Steel Structure ◽  
Light Weight ◽  
Vibrational Modes ◽  
Characteristic Analysis ◽  
Natural Period ◽  
Infill Walls ◽  
Temporary Structure ◽  
Prefabricated Houses

Prefabricated house is a new kind of temporary structure. It has the advantages of extensibility and diversity, and it is also easy to assemble and disassemble. This paper performed the dynamic characteristic test of 4 prefabricated houses of light-weight steel structure on the site by using SVSA, and got the natural frequencies, damping ratios and vibrational modes of these structures. To study the effects of infill walls to the dynamic characteristic of structures, two different modes were built. By comparing the results of numerical evaluation and actual data, the paper analyzed the dynamic characteristic of prefabricated houses of light-weight steel structure. Analysis suggests that the vibrational modes of prefabricated houses of light-weight steel structure are in shear shape, and the damping ratios are between 0.6% and 2%. The infill walls and the pull rods between columns can shorten the natural period of structures, so the computation period should be reduced in the aseismatic design.

Optimization of a Light-Weight Composite Blast Containment Vessel Structural Response

2007 ◽  
Author(s):  
Jagadeep Thota ◽  
Ashok K. Ayyaswamy ◽  
Mohamed B. Trabia ◽  
Brendan J. O’Toole
Keyword(s):  
Structural Integrity ◽  
Optimization Technique ◽  
Structural Response ◽  
Optimization Procedure ◽  
Element Model ◽  
Light Weight ◽  
Gusset Plates ◽  
Containment Vessel ◽  
Plastic Composite ◽  
Design Variables

This paper proposes an optimization technique for increasing the structural integrity of a light-weight composite blast containment vessel. The vessel is cylindrical with two hemispherical ends. It has a steel liner that is internally reinforced with throttles and gusset plates and wrapped with a basalt-plastic composite. A finite element model of the blast containment vessel was proposed and verified in an earlier work. The parameters of the vessel are incorporated within an iterative optimization procedure to decrease the peak strains within the vessel, which are caused by internal blast loading due to an explosive charge placed at the center of the vessel. The procedure is validated for different initial guesses of the design variables.

Behavior of Confined Masonry Walls with Openings under In-Plane and Out-of-Plane Loads

2018 ◽  
Vol 34 (2) ◽  
pp. 817-841 ◽  
Author(s):  
Vaibhav Singhal ◽  
Durgesh C. Rai
Keyword(s):  
Structural Integrity ◽  
Solid Wall ◽  
Ground Motions ◽  
Masonry Walls ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Severe Damage ◽  
Confined Masonry ◽  
Load Carrying ◽  
Out Of Plane

Six half-scaled wall panels were tested to investigate the effect of openings on their load-carrying capacity; these walls were subjected to a sequence of slow cyclic in-plane drifts and shake table–generated out-of-plane ground motions. Two specimens were masonry-infilled frames with and without openings. The other four specimens were confined-masonry (CM) walls, with one solid wall and three walls with openings bounded by reinforced-concrete (RC) confining elements on all sides. The infill walls demonstrated higher risk of out-of-plane collapse, whereas the CM walls maintained structural integrity and out-of-plane stability. The test results clearly indicate the necessity of confinement all around the openings for good seismic performance. The confining scheme with no continuous horizontal bands was ineffective in confining wall piers at large drifts, and piers remain vulnerable to out-of-plane collapse due to severe damage. However, the wall with continuous horizontal bands at the lintel and sill levels was not only able to compensate for deficiencies in strength due to the presence of openings, but also achieved a better overall behavior due to more distributed damage and greater ductility.

New Waterproof Insulation Roof Building Materials and the Construction

2011 ◽  
Vol 261-263 ◽  
pp. 633-637 ◽  
Author(s):  
Jie Zhang
Keyword(s):  
Building Material ◽  
Building Materials ◽  
Salt Water ◽  
Water Repellent ◽  
Insulation Material ◽  
Light Weight ◽  
Expanded Perlite ◽  
Fatty Acid Salt ◽  
Construction Period ◽  
Flat Roof

In this paper, Portland cement was used as cementitious material and expanded perlite was used as insulation material. Fatty acid salt water repellent was also added to make this new thermal insulation, waterproof and light weight roof building material. It can be cast onto flat roof during construction or made into tiles and laid onto sloping roofs. This new roof building material had short construction period and can be completed in a one-time process. It may replace conventional construction method of applying insulation and waterproof materials separately.

Structural Response Optimization of a Light-Weight Composite Blast Containment Vessel

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Jagadeep Thota ◽  
Mohamed B. Trabia ◽  
Brendan J. O’Toole ◽  
Ashok K. Ayyaswamy
Keyword(s):  
Structural Integrity ◽  
Optimization Technique ◽  
Structural Response ◽  
Optimization Procedure ◽  
Element Model ◽  
Light Weight ◽  
Computationally Efficient ◽  
Containment Vessel ◽  
Plastic Composite ◽  
Design Variables

This paper proposes an optimization technique for increasing the structural integrity of a light-weight composite blast containment vessel. The vessel is cylindrical with two hemispherical ends. It has a steel liner that is internally reinforced with throttles and gusset plates and wrapped with a basalt-plastic composite. A computationally-efficient finite element model of the blast containment vessel was proposed and verified in an earlier work. The parameters of the vessel are incorporated within an iterative optimization procedure to decrease the peak strains within the vessel, which are caused by internal blast loading due to an explosive charge placed at the center of the vessel. The results of the proposed procedure are validated for different initial guesses of the design variables.

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