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Diagnostic Investigation of Hydro Electric Project Made Easy with Remote Operated Vehicle
Alex Varughese,
Hari Dev,
Sohan Lal Gupta
Issue:
Volume 6, Issue 1, January 2018
Pages:
1-4
Received:
13 September 2017
Accepted:
11 October 2017
Published:
21 November 2017
Abstract: Regular safety appraisal of dam and its appurtenant structures is recommended by dam safety committees. Monitoring of dam is carried out in many ways like Visual inspections, Instrumentation, Non-Destructive Testing (NDT) and Underwater Inspection using divers, Remote Operated Vehicle (ROV) and Geophysical methods. In dealing with the safety problems during the operation, maintenance and surveillance of dams, it is essential to carefully collect process and study all available information. Underwater scanning, using ROV, is a good solution for assessment of health of submerged portion of structures. This paper presents case studies of underwater scanning of an important Hydro Electric Project using the Remote Operated Vehicle for the diagnostic investigation.
Abstract: Regular safety appraisal of dam and its appurtenant structures is recommended by dam safety committees. Monitoring of dam is carried out in many ways like Visual inspections, Instrumentation, Non-Destructive Testing (NDT) and Underwater Inspection using divers, Remote Operated Vehicle (ROV) and Geophysical methods. In dealing with the safety proble...
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Researching on Buckling Performance of Corrugated Steel Web
Zhu Xudong,
Li Ming,
Li Yong
Issue:
Volume 6, Issue 1, January 2018
Pages:
5-10
Received:
5 December 2017
Published:
6 December 2017
Abstract: The paper mainly studies buckling performance about corrugated steel web composite box girder of corrugated steel web under the action of a shear. Compare the two results of the corrugated steel web that calculating critical buckling stress through Abaqus finite element software calculating and theory formula. Obtain buckling strength of the model by giving the model initial defects under the elastic condition merely. In this paper, research trend of the buckling strength of corrugated steel web plate through changing the thickness of corrugated steel web, Angle, length of straight and wave height and the size of the corrugated steel web in practical engineering designing provide a certain references.
Abstract: The paper mainly studies buckling performance about corrugated steel web composite box girder of corrugated steel web under the action of a shear. Compare the two results of the corrugated steel web that calculating critical buckling stress through Abaqus finite element software calculating and theory formula. Obtain buckling strength of the model ...
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Study on Mechanical Properties of Expand Polystyrene
Zhongkun Zhang,
Denghua Zuo,
Wentao Shang,
Linlin Wang,
Jianbo Zheng,
Hui Ma,
Lu Chen,
Baohuai Yang,
Yusheng Qin,
Changming Wang
Issue:
Volume 6, Issue 1, January 2018
Pages:
11-15
Received:
5 December 2017
Published:
6 December 2017
Abstract: Expand Polystyrene is simply written as EPS, and it is newly used as a kind of embankment filler. Based on abroad studies to EPS mechanical properties, a further research on EPS has been done in this paper. The triaxial test is used for the study. Duncan-Chang parameters of EPS are studied in the test. EPS block bearing test is studied by means of finite element method, and the Duncan-Chang parameters obtained from EPS triaxial test are proved to be right. The application value and the application extent are pointed out in conclusion, as is of valuable reference to real geotechnical engineering projects.
Abstract: Expand Polystyrene is simply written as EPS, and it is newly used as a kind of embankment filler. Based on abroad studies to EPS mechanical properties, a further research on EPS has been done in this paper. The triaxial test is used for the study. Duncan-Chang parameters of EPS are studied in the test. EPS block bearing test is studied by means of ...
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Strength Studies on Different Grades of Concrete Considering Fire Exposure
Kiran Kumar Poloju,
Ram Kishore Manchiryal,
Chiranjeevi Rahul
Issue:
Volume 6, Issue 1, January 2018
Pages:
16-23
Received:
7 November 2017
Accepted:
16 November 2017
Published:
14 December 2017
Abstract: Concrete is generally strong in compression and weak in tension also it resist against fire. Cement concrete is a complex mixture of different materials, for which the properties may alter in different environmental conditions. The behavior of concrete is depends on difference in temperatures and its mix proportions. The principle effects in the concrete due to elevated temperatures are loss in compressive strength, loss in weight or mass, change in color and spalling of concrete. The objective of this research attempt was to prove experimentally the effects on the behavior of concrete under elevated temperatures of different grades (M20, M40 and M60) of concrete. The compressive strength was determined at different temperatures, thus providing scope of determining loss in strength. In addition, effects on strength under cooling for different grades of concrete were studied. The specimens were kept in oven at certain temperatures (200°C, 400°C, 600°C, and 800°C) for 1 hour at constant temperatures. Non-destructive testing (NDT) methods, i.e. Rebound hammer test was adopted to study the changes in surface hardness of concrete specimens subjected to elevated temperatures.
Abstract: Concrete is generally strong in compression and weak in tension also it resist against fire. Cement concrete is a complex mixture of different materials, for which the properties may alter in different environmental conditions. The behavior of concrete is depends on difference in temperatures and its mix proportions. The principle effects in the co...
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Seismic Performance of Reinforced Concrete Buildings with Masonry Infill
Girma Zewdie Tsige,
Adil Zekaria
Issue:
Volume 6, Issue 1, January 2018
Pages:
24-33
Received:
24 September 2017
Accepted:
23 October 2017
Published:
2 January 2018
Abstract: Unreinforced masonry Infills modify the behavior of framed structures under lateral loads; however, in practice, the infill stiffness is commonly ignored in frame analysis, resulting in an under-estimation of stiffness and natural frequency. The structural effect of hollow concrete block infill is generally not considered in the design of columns as well as other structural components of RC frame structures. The hollow concrete block walls have significant in-plane stiffness contributing to the stiffness of the frame against lateral load. The scope of present work was to study seismic performance of reinforced concrete buildings with masonry infill in medium rise building. The office medium rise building is analyzed for earthquake force by considering three type of structural system. i.e. Bare Frame system, partially-infilled and fully- Infilled frame system. Effectiveness of masonry wall has been studied with the help of five different models. Infills were modeled using the equivalent strut approach. Nonlinear static analyses for lateral loads were performed by using standard package ETABS, 2015 software. The comparison of these models for different earthquake response parameters like base shear vs roof displacement, Story displacement, Story shear and member forces are carried out. It is observed that the seismic demand in the bare frame is significantly large when infill stiffness is not considered, with larger displacements. This effect, however, is not found to be significant in the infilled frame systems. The results are described in detail in this paper.
Abstract: Unreinforced masonry Infills modify the behavior of framed structures under lateral loads; however, in practice, the infill stiffness is commonly ignored in frame analysis, resulting in an under-estimation of stiffness and natural frequency. The structural effect of hollow concrete block infill is generally not considered in the design of columns a...
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Foundation Investigations for the Bhaunrat Dam Project – A Case Study
Shahid Noor,
Rajaretnam Chitra,
Manish Gupta,
Amardeep Singh
Issue:
Volume 6, Issue 1, January 2018
Pages:
34-38
Received:
28 November 2017
Accepted:
18 December 2017
Published:
5 January 2018
Abstract: The geotechnical investigations play an important role in economic viability and structural stability of a dam project. The geotechnical investigation for dam project involves the borrow area investigations and foundation investigations. The borrow area locations and characteristics decide the economic viability of earthen dam project. Borrow area investigations characterizes the construction material in the vicinity of dam site, depth of construction material, extent of construction material. The foundation investigation is carried out to evaluate the compactness for foundation and abutments for the dam project, treatment to be given to foundation and depth of excavation of foundation. The extent of foundation investigation depends upon the site conditions but it provide the information regarding type of the soil or rock strata in the foundation or abutment at dam site, depth of rock, water table and locations of buried channels, seams, joints and fissures etc. The foundation investigations decide the structural safety of a dam project. The present paper presents the foundation investigations carried out for construction of Bhaunrat Dam Project, Uttar Pradesh.
Abstract: The geotechnical investigations play an important role in economic viability and structural stability of a dam project. The geotechnical investigation for dam project involves the borrow area investigations and foundation investigations. The borrow area locations and characteristics decide the economic viability of earthen dam project. Borrow area ...
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Determination of Optimum Cement Content for Stabilization of Soft Soil and Durability Analysis of Soil Stabilized with Cement
Md Ali Ashraf,
S. M. Shazeebur Rahman,
Md Omar Faruk,
Md Abul Bashar
Issue:
Volume 6, Issue 1, January 2018
Pages:
39-43
Received:
4 December 2017
Accepted:
18 December 2017
Published:
5 January 2018
Abstract: This research was aimed at finding the optimum cement content for achieving maximum compressive strength and stabilization in soft soil found in the periphery of the city of Chittagong. But, gaining strength was not considered enough unless it can be proved that strength was gained without compromising the durability. As such, durability test was performed on the samples stabilized with different percentages of cement. In this research three different soil samples were used. The samples were collected from three different areas within the city where future expansion of the city is expected. Six different percentages of cement by weight of soil: 0%, 2%, 4%, 6%, 8%, and 10% were used. Cement was mixed with soil at optimum moisture content. Cubes were casted and their compressive strengths assessed after a curing period of 7, 14 & 28 days. The durability test was done in two different cycles: 2 days wetting-drying and 7 days wetting-drying within a time frame of 28 days. The volume and weight were monitored after completion of each cycle of wetting and drying. The performance of the soils modified with different percentages of cement were assessed using Standard Proctor Test, Unconfined Compression Test and Durability Test. It was found that compressive strengths in the samples under test increased with the increase of cement content up to 8%. But when cement content is increased above 8%, the compressive strength increased but in a slower rate. At the end of durability test, it was observed that volume, and weight of the soil samples produced with 2, 4 and 6% cement changes with the variation in wetting and drying periods. But when the cement percentage is increased by 6%, preferably increased to 8%, no appreciable change in weight and volume were observed after the wetting and drying cycles. The samples going through the two days wetting and drying cycles under durability test showed greater unconfined compressive strength compared to samples going through seven days durability cycle of wetting and drying. It may be mentioned here that the three soil samples stabilized with cement did not show any major degradation in compressive strength during durability test.
Abstract: This research was aimed at finding the optimum cement content for achieving maximum compressive strength and stabilization in soft soil found in the periphery of the city of Chittagong. But, gaining strength was not considered enough unless it can be proved that strength was gained without compromising the durability. As such, durability test was p...
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Improved Prediction Model for Dynamic Resilient Modulus of Subgrade Silty Clay in Eastern Hunan and Its Relevant Finite Element Method Implementation
Dong Cheng,
Zheng Guo-yong,
Liu Wen-jie,
Zhou Lun,
Zhang Rui-lei
Issue:
Volume 6, Issue 1, January 2018
Pages:
44-54
Received:
30 January 2018
Published:
3 February 2018
Abstract: With the enhancement of transportation speed and axle load, dynamic response of subgrade increases significantly. In order to improve the calculation accuracy of subgrade response under complex stress state, it is necessary to use dynamic indicators instead of static indicators in calculative process. For the sake of investigating the influence factor of dynamic resilient modulus of subgrade silty clay in Eastern Hunan, resilient modulus tests were carried out by conducting repeated load tri-axial tests. Based on available model, an improved resilient modulus prediction model considering four parameters was proposed by introducing k4. Corresponding accurate consistent tangent stiffness matrix was derived. Afterward, the improved model was implemented into finite element method software and verification work was put forward both on single element and pavement-subgrade structure. Finally, calculated results were compared with in-site measured results. Study achievements demonstrate that the improved model exhibits a higher precision and efficiency on single element because k4 can better adjust the affecting proportion of octahedral shear stress. When applied to analysis on pavement-subgrade structure, the improved model can reflect subgrade resilient modulus distribution and evolution more factually. In addition, numerical calculated result nearly coincides with measured results, which shows the application value of the improved model.
Abstract: With the enhancement of transportation speed and axle load, dynamic response of subgrade increases significantly. In order to improve the calculation accuracy of subgrade response under complex stress state, it is necessary to use dynamic indicators instead of static indicators in calculative process. For the sake of investigating the influence fac...
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