Pub Date : 2021-07-30DOI: 10.4236/ojce.2021.113017
N. Ali
In many sites on Egypt desert roads collapsible soils is broadly classified as a problematic soils containing silty fine sand which is cemented with low density and low degree of saturation which is susceptible to a large and sudden reduction in their volume upon inundation, with or without vibration in its stress. Four sites have been studied for new urban, roads and industry work sits, related to increase in natural water content. These soils go through radical rearrangement of their particles, causing sudden changes in the stress-deformation behavior which cause differential settlement of foundation and roads. This change in volume can lead to foundation failures and worth of damages under ground public facilities and infrastructure. In this study, the search program is developed to establish their different behavior under wetting in two phases: field and laboratory work. The obtained results are useful in mapping the trend of the factors affected in assessing soil collapsibility rate or collapse potentials which are observed in construction with volume change problems. The major factors observed are the natural structure skeleton of the soil particle and its grain size and mechanism of soil sedimentation. The field collapse potentials value assigned for these tested sites along Alexandria—Cairo desert road indicated that the field measured collapsibility potentials are smaller than those measured on the same extracted undisturbed samples in laboratory by 15%, which can be saved in coast, change in proposed collapsibility improvement method and change in select foundation type. Also, field tests evaluate the collapsibility rate with time and highlight that environmental history and natural soil structure in field are the important factors affected on these soil collapse, and also, knowledgeable by collapsible soils during wetting in these sites studied.
{"title":"Practical Engineering Behavior of Egyptian Collapsible Soils, Laboratory and In-Situ Experimental Study","authors":"N. Ali","doi":"10.4236/ojce.2021.113017","DOIUrl":"https://doi.org/10.4236/ojce.2021.113017","url":null,"abstract":"In many sites on Egypt desert roads collapsible soils is broadly classified as a problematic soils containing silty fine sand which is cemented \u0000with low density and low degree of saturation which is susceptible to a large \u0000and sudden reduction in their volume upon \u0000inundation, with or without vibration in its stress. Four sites have been \u0000studied for new urban, roads and industry work sits, related to increase in natural water \u0000content. These soils go through radical rearrangement of \u0000their particles, causing sudden changes in the stress-deformation behavior \u0000which cause differential settlement of foundation and roads. \u0000This change in volume can lead to foundation failures and \u0000worth of damages under ground public facilities and infrastructure. In this \u0000study, the search program is developed to establish their different behavior under wetting in two \u0000phases: field and laboratory work. The obtained results are useful in mapping \u0000the trend of the factors affected in \u0000assessing soil collapsibility rate or collapse potentials which are observed in construction with volume change problems. The major factors \u0000observed are the natural structure skeleton of the soil particle and its grain \u0000size and mechanism of soil sedimentation. The field collapse potentials value \u0000assigned for these tested sites along Alexandria—Cairo \u0000desert road indicated that the field measured collapsibility potentials are \u0000smaller than those measured on the same extracted undisturbed samples in laboratory \u0000by 15%, which can be saved in coast, change in proposed collapsibility improvement method and \u0000change in select foundation type. Also, field tests evaluate the collapsibility \u0000rate with time and highlight that environmental history and natural soil structure \u0000in field are the important factors affected on these soil collapse, and also, \u0000knowledgeable by collapsible soils during wetting in these sites studied.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130243306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.4236/ojce.2021.113020
Yi Wu
Expansive soils can pose tough issues to civil engineering applications. In a typical year, expansive soils can cause a greater financial loss than earthquakes, floods, hurricanes and tornadoes combined. Various means have been studied to tackle problems associated with expansive soils. The majority of the methods are based on treatment of the soils. While the methods may be effective in some cases, their limitations are also obvious: The treatment normally involves complex processes and may not be eco-friendly in the long run. In many cases, the effectiveness of the treatment is uncertain. A retaining system that maintains a constant lateral pressure is proposed, which consists of three components: the retaining sheet, the slip-force device and the bracing column. The retaining sheet bears the pressure exerted by expansive backfills and is not embedded into the soils. Placed between the retaining sheet and bracing column, the slip-force device permits displacement of the retaining sheet but keeps the force on the sheet and the bracing column constant. The governing equation of the motion of the piston in the slip-force device is derived and a numerical simulation of a practical case is conducted based on the derived governing equation. Numerical results show that as the expansive soil swell, the spring force will increase and the piston will move accordingly. When the pressure of the oil in chamber reaches the open threshold of the unidirectional relief valve, the valve will open and the spring force and the oil pressure in the chamber will keep constant. The results also show that some parameters, such as damping ratio, have very slight influences on the device behavior, say 2 × 10-6 or even 4.8 × 10-9. Theoretical and numerical studies prove the effectiveness of the proposed retaining system.
{"title":"A Slip-Force Device for Maintaining Constant Lateral Pressure on Retaining Structures in Expansive Soils","authors":"Yi Wu","doi":"10.4236/ojce.2021.113020","DOIUrl":"https://doi.org/10.4236/ojce.2021.113020","url":null,"abstract":"Expansive soils can pose tough issues to civil engineering applications. \u0000In a typical year, expansive soils can cause a greater financial loss than \u0000earthquakes, floods, hurricanes and tornadoes combined. Various means have been \u0000studied to tackle problems associated with expansive soils. The majority of the \u0000methods are based on treatment of the soils. While the methods may be effective \u0000in some cases, their limitations are also obvious: The treatment normally \u0000involves complex processes and may not be eco-friendly in the long run. In many \u0000cases, the effectiveness of the treatment is uncertain. A retaining system that \u0000maintains a constant lateral pressure is proposed, which consists of three \u0000components: the retaining sheet, the slip-force device and the bracing column. \u0000The retaining sheet bears the pressure exerted by expansive backfills and is \u0000not embedded into the soils. Placed between the retaining sheet and bracing \u0000column, the slip-force device permits displacement of the retaining sheet but \u0000keeps the force on the sheet and the bracing column constant. The governing \u0000equation of the motion of the piston in the slip-force device is derived and a \u0000numerical simulation of a practical case is conducted based on the derived \u0000governing equation. Numerical results show that as the expansive soil swell, the \u0000spring force will increase and the piston will move accordingly. When the \u0000pressure of the oil in chamber reaches the \u0000open threshold of the unidirectional relief valve, the valve will open and the \u0000spring force and the oil pressure in the chamber will keep constant. The results \u0000also show that some parameters, such as damping ratio, have very slight \u0000influences on the device behavior, say 2 × 10-6 or even 4.8 × 10-9. \u0000Theoretical and numerical studies prove the effectiveness of the proposed \u0000retaining system.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125560341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.4236/ojce.2021.113019
Mostafa H. Hassaan, M. Elmasry, Nabil Hassan EL Ashkar
Nuclear power plants (NPPs) are considered as the main source for generating electricity nowadays in some countries. The effect of impact of heavy fully loaded aeroplane such as (Boeing 747-200c) causes leakage of the radiation through the cracks generated on the external RC containment of NPPs, and this leads to severe damage for humans and cities. In this research paper, external RC containment is modeled using ANSYS and hit by Boeing 747-200c which is the heavier aeroplane compared to other jets and causes severe damage for external RC containment. In addition, the impact location for Boeing 747-200c is considered at 30 m vertical height. RC containment response was studied after the impact of an aeroplane and a proposed structural health monitoring technique is applied using embedded sensors in order to detect and locate the embedded cracks that is generated due to the effect of impact of heavy aeroplane. It was concluded that RC containment is intact except for the impact region which is damaged. An experimental program was applied on a part of the element in ANSYS which is away from the impact region. Four specimens were cast using heavy weight concrete in laboratory. Three cracked specimens consist of different lengths of vertical cracks which represent different times of impact in order to replicate crack propagation as in ANSYS. The cracks are simulated inside laboratory specimens using failure criteria. The parameters used in detecting the cracks for specimens are the percentage change in electrical resistivity and Decimal Logarithm Resistivity Anisotropy (DLRA) at which they give a good indication for the presence of the crack.
{"title":"Structural Health Monitoring for Reinforced Concrete Containment Using Inner Electrical Resistivity Method","authors":"Mostafa H. Hassaan, M. Elmasry, Nabil Hassan EL Ashkar","doi":"10.4236/ojce.2021.113019","DOIUrl":"https://doi.org/10.4236/ojce.2021.113019","url":null,"abstract":"Nuclear power plants (NPPs) are considered as the main source for generating \u0000electricity nowadays in some countries. The effect of impact of heavy fully \u0000loaded aeroplane such as (Boeing 747-200c) causes leakage of the radiation \u0000through the cracks generated on the external RC containment of NPPs, and this \u0000leads to severe damage for humans and cities. In this research paper, external \u0000RC containment is modeled using ANSYS and hit by Boeing 747-200c which is the heavier \u0000aeroplane compared to other jets and causes severe damage for external RC \u0000containment. In addition, the impact location for Boeing 747-200c is considered \u0000at 30 m vertical height. RC containment response was studied after the impact \u0000of an aeroplane and a proposed structural health monitoring technique is \u0000applied using embedded sensors in order to detect and locate the embedded \u0000cracks that is generated due to the effect of impact of heavy aeroplane. It was \u0000concluded that RC containment is intact except for the impact region which is \u0000damaged. An experimental program was applied on a part of the element in ANSYS \u0000which is away from the impact region. Four specimens were cast using heavy \u0000weight concrete in laboratory. Three cracked specimens consist of different \u0000lengths of vertical cracks which represent different times of impact in order \u0000to replicate crack propagation as in ANSYS. The cracks are simulated inside laboratory \u0000specimens using failure criteria. The parameters used in detecting the cracks \u0000for specimens are the percentage change in electrical resistivity and Decimal \u0000Logarithm Resistivity Anisotropy (DLRA) at which they give a good indication \u0000for the presence of the crack.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130651326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.4236/ojce.2021.113016
Isooba John, M. Bangi, M. Lawrence
Filler and binder make up a small proportion of bituminous mixtures, hence they are considered as important ingredients of mixtures. Sometimes due to equipment error during production, some mixtures retain extra or a reduced amount of filler or binder as compared to the design mix formula. It is thought that the poor performance of bituminous mixtures is a result of inadequate proportioning of materials and the use of inappropriate compaction tools. This study was intended to appreciate the influence of contents of filler and binder in relation to durability in asphalt mixtures. Filler used was crushed stone passing 0.075 mm sieve, while the binder was 35/50 penetration grade. Several trial mixes were prepared following Ugandan specifications for Road and Bridge Works, and the Asphalt Institute in MS-2. Marshall design method was used, studying volumetric properties with an average stability value of 22.3 kN, average flow value of 3.7 mm, VA of 4.4%, VFB of 69.3%, and VMA of 14.2%. Also, compaction of mixtures to assess its performance at optimum filler and binder contents was done. Compaction was done using an Automatic Impact Hammer, a Vibrating Hammer, and a Superpave Gyratory compactor aimed at simulating secondary compaction by traffic and assessing the retained air voids which was 3.3%, 1.3%, and 0.7% respectively. Generally, in bituminous mixtures when a vibrating hammer or a gyratory compactor is recommended for compaction, coarser mixes would be the best choice.
填料和粘结剂在沥青混合料中所占比例很小，因此被认为是混合料的重要组成部分。有时由于生产过程中的设备错误，与设计混合配方相比，某些混合物保留了额外或减少的填料或粘结剂量。据认为，沥青混合料的性能差是由于材料比例不足和使用不适当的压实工具造成的。本研究旨在了解填料和粘结剂含量对沥青混合料耐久性的影响。填料为通过0.075 mm筛的碎石，粘结剂为35/50渗透等级。按照乌干达道路和桥梁工程规范和MS-2沥青研究所的规范，准备了几种试验混合料。采用Marshall设计方法，研究了平均稳定值为22.3 kN，平均流量为3.7 mm, VA为4.4%，VFB为69.3%，VMA为14.2%的体积性能。此外，还对混合物进行了压实，以评估其在最佳填料和粘结剂含量下的性能。使用自动冲击锤、振动锤和Superpave旋转压实机进行压实，旨在模拟交通的二次压实，并评估保留空隙率，分别为3.3%、1.3%和0.7%。通常，在沥青混合物中，当建议使用振动锤或旋转压实机进行压实时，较粗的混合物将是最佳选择。
{"title":"Effect of Filler and Binder Contents on Air Voids in Hot-Mix Asphalt for Road Pavement Construction","authors":"Isooba John, M. Bangi, M. Lawrence","doi":"10.4236/ojce.2021.113016","DOIUrl":"https://doi.org/10.4236/ojce.2021.113016","url":null,"abstract":"Filler \u0000and binder make up a small proportion of bituminous mixtures, hence they are \u0000considered as important ingredients of mixtures. Sometimes due to equipment \u0000error during production, some mixtures retain extra or a reduced amount of \u0000filler or binder as compared to the design mix formula. It is thought that the \u0000poor performance of bituminous mixtures is a result of inadequate proportioning \u0000of materials and the use of inappropriate compaction tools. This study was \u0000intended to appreciate the influence of contents of filler and binder in \u0000relation to durability in asphalt mixtures. Filler used was crushed stone \u0000passing 0.075 mm sieve, while the binder was 35/50 penetration grade. Several \u0000trial mixes were prepared following Ugandan specifications for Road and Bridge \u0000Works, and the Asphalt Institute in MS-2. Marshall design method was used, \u0000studying volumetric properties with an average stability value of 22.3 kN, \u0000average flow value of 3.7 mm, VA of 4.4%, VFB of 69.3%, and VMA of 14.2%. Also, \u0000compaction of mixtures to assess its performance at optimum filler and binder \u0000contents was done. Compaction was done using an Automatic Impact Hammer, a \u0000Vibrating Hammer, and a Superpave Gyratory compactor aimed at simulating \u0000secondary compaction by traffic and assessing the retained air voids which was \u00003.3%, 1.3%, and 0.7% respectively. Generally, in bituminous mixtures when a \u0000vibrating hammer or a gyratory compactor is recommended for compaction, coarser \u0000mixes would be the best choice.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134032983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.4236/ojce.2021.113021
S. Bassan
The primary purpose of an interchange is to enable an appropriate level of access to the freeway in a safe and beneficial way to the driver. It improves road safety and traffic operation by reducing or eliminating traffic conflicts that would occur if grade separation were not provided (e.g. intersection). Crossing conflicts are eliminated and turning conflicts are either eliminated or minimized. The paper focuses on sight distance criteria in the geometric design of interchanges and junctions, specifically, implementation of stopping sight distance (SSD) and decision sight distance (DSD). These issues incorporate implementation of sight distance policy for: ramps’ geometric design, ramp terminals’ components, and basic lanes’ reduction. These sight distance criteria can alleviate safety by reducing conflicts and confusion to the driver and by keeping alignment simple, direct, and consistent. Specifically, DSD affects traffic control and intelligent transportation systems applications.
{"title":"Interchange Sight Distance and Design: Aspects and Implementation","authors":"S. Bassan","doi":"10.4236/ojce.2021.113021","DOIUrl":"https://doi.org/10.4236/ojce.2021.113021","url":null,"abstract":"The primary purpose of an interchange is to enable \u0000an appropriate level of access to the freeway in a safe and beneficial way to \u0000the driver. It improves road safety and traffic operation by reducing or \u0000eliminating traffic conflicts that would occur if grade separation were not \u0000provided (e.g. intersection). Crossing conflicts are eliminated and turning \u0000conflicts are either eliminated or minimized. The paper focuses on sight \u0000distance criteria in the geometric design of interchanges and junctions, \u0000specifically, implementation of stopping sight distance (SSD) and decision \u0000sight distance (DSD). These issues incorporate implementation of sight distance \u0000policy for: ramps’ geometric design, ramp terminals’ components, and basic \u0000lanes’ reduction. These sight distance criteria can alleviate safety by \u0000reducing conflicts and confusion to the driver and by keeping alignment simple, \u0000direct, and consistent. Specifically, DSD affects traffic control and \u0000intelligent transportation systems applications.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116776066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.4236/ojce.2021.113018
S. Na, Woong-Geol Lee, M. Song
Recently, a large amount of circulating fluidized bed boiler ash (CFBA) and desulfurization gypsum (DSG) has been produced, and it is essential to develop technology to utilize them. These materials have CaO and SO3, which are considered to be a stimulant for blast furnace slag (BFS). This study presents an experimental investigation of the compressive strength and heavy metal ions immobilization properties of cement-free materials comprising CFBA, BFS, and DSG. The feasibility of manufacturing foamed concrete using these materials was examined, and field test of foamed concrete was conducted. Experimentally, the flow, compressive strength, and heavy metal ions concentration were evaluated via inductively coupled plasma atomic emission spectroscopy (ICP-AES) of the paste and foamed concrete. The experimental investigation revealed the self-healing hardening ability of fluidized bed boiler ash. In addition, the compressive strength was increased with the increasing replacement rates of BFS and DSG in the CFBA paste, and the compressive strength of 14.6 - 17.2 MPa was recorded over 28 days of curing. From the result obtained, the feasibility of manufacturing foamed concrete with a foam volume of 120 L, incorporating the aforementioned materials, is confirmed. It was also found that after 28 days of age, a 7.9-MPa compressive strength of the foamed concrete was attained, and heavy metal ions elution in this foamed concrete was also significantly reduced. Therefore, CFBA, BFS, and DSG could be used as a binder for the foamed concrete.
{"title":"Hardening Properties of Foamed Concrete with Circulating Fluidized Bed Boiler Ash, Blast Furnace Slag, and Desulfurization Gypsum as the Binder","authors":"S. Na, Woong-Geol Lee, M. Song","doi":"10.4236/ojce.2021.113018","DOIUrl":"https://doi.org/10.4236/ojce.2021.113018","url":null,"abstract":"Recently, \u0000a large amount of circulating fluidized bed boiler ash (CFBA) and desulfurization \u0000gypsum (DSG) has been produced, and it is essential to develop technology to \u0000utilize them. These materials have CaO and SO3, which are considered to be a stimulant for blast furnace slag (BFS). This study \u0000presents an experimental investigation of the compressive strength and heavy \u0000metal ions immobilization properties of cement-free materials comprising CFBA, \u0000BFS, and DSG. The feasibility of manufacturing foamed concrete using these \u0000materials was examined, and field test of foamed concrete was conducted. \u0000Experimentally, the flow, compressive strength, and heavy metal ions \u0000concentration were evaluated via inductively coupled plasma atomic emission \u0000spectroscopy (ICP-AES) of the paste and foamed concrete. The experimental investigation \u0000revealed the self-healing hardening ability of fluidized bed boiler ash. In \u0000addition, the compressive strength was increased with the increasing \u0000replacement rates of BFS and DSG in the CFBA paste, and the compressive \u0000strength of 14.6 - 17.2 MPa was recorded over 28 days of curing. From the result obtained, \u0000the feasibility of manufacturing foamed concrete with a foam volume of 120 L, incorporating the aforementioned materials, is confirmed. It was \u0000also found that after 28 days of age, a 7.9-MPa compressive strength of the \u0000foamed concrete was attained, and heavy metal ions elution in this foamed \u0000concrete was also significantly reduced. Therefore, CFBA, BFS, and DSG could be \u0000used as a binder for the foamed concrete.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"78 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132728442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.4236/OJCE.2021.112011
Jinchao Zhang, Xiaolong Li, C. Fang, Xingquan Mao, Wenyu Li, Longyun Li, Yi Zhou
The load-response correlation is a great concern for the management and maintenance agency of bridges. Based on both the load test data and the long-term structural health monitoring data, this study aims to characterize the variation in the girder-end longitudinal displacement of a long-span suspension bridge, i.e., the Zhaoyun Bridge in Guangdong Province of China. The load test provides a valuable chance to investigate the structural deformation in high loading levels, while the structural health monitoring system records the real-time, in-site, and long-term measurements in the normal operational stage of bridges. During the load test, the movement direction of the main girder is found to depend on the relative position of the center of gravity of the girder and the loading vehicles. However, over the period of normal operation, the quasi-static displacement at the ends of the main girder along the bridge axis is dominated by the temperature variations, rather than the traffic loading. The temperature-induced deformation is considerable so it should be filtered out from the structural total responses to highlight the live load effects or the anomalies of the bridge. As a case study, the temperature-displacement baseline model of the Zhaoyun Bridge is established and then utilized to identify the erroneous measurements in the structural health monitoring system. This paper serves as a reference for the structural behavior interpretation and performance evaluation of similar bridges.
{"title":"Study on the Girder-End Displacement of a Suspension Bridge Based on Field Measurements","authors":"Jinchao Zhang, Xiaolong Li, C. Fang, Xingquan Mao, Wenyu Li, Longyun Li, Yi Zhou","doi":"10.4236/OJCE.2021.112011","DOIUrl":"https://doi.org/10.4236/OJCE.2021.112011","url":null,"abstract":"The \u0000load-response correlation is a great concern for the management and \u0000maintenance agency of bridges. Based on both the load test data and the \u0000long-term structural health monitoring data, this study aims to characterize \u0000the variation in the girder-end longitudinal displacement of a long-span \u0000suspension bridge, i.e., the Zhaoyun \u0000Bridge in Guangdong Province of China. The load test provides a valuable chance \u0000to investigate the structural deformation in high loading levels, while the \u0000structural health monitoring system records the real-time, in-site, and \u0000long-term measurements in the normal operational stage of bridges. During the \u0000load test, the movement direction of the main girder is found to depend on the \u0000relative position of the center of gravity of the girder and the loading \u0000vehicles. However, over the period of normal operation, the quasi-static \u0000displacement at the ends of the main girder along the bridge axis is dominated \u0000by the temperature variations, rather than the traffic loading. The \u0000temperature-induced deformation is considerable so it should be filtered out \u0000from the structural total responses to highlight the live load effects or the \u0000anomalies of the bridge. As a case study, the temperature-displacement baseline \u0000model of the Zhaoyun Bridge is established and then utilized to identify the \u0000erroneous measurements in the structural health monitoring system. This paper \u0000serves as a reference for the structural behavior interpretation and \u0000performance evaluation of similar bridges.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117351627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.4236/ojce.2021.112015
M. Balabušić
Theoretical approach with analytical and numerical procedure for determination initial displacement of a reinforced and prestressed concrete members, simple and cantilever beams, loaded by axial forces and bending moments is proposed. It is based on the principle of minimum potential energy with equality of internal and external forces. The equations for strain internal energy have been derived, including compressed and tensile concrete and reinforcement. The energy equations of the external forces with axial flexural displacement effects have been derived from the assumed sinusoidal curve. The trapezoid rule is applied to integrate the segment strain energy. The proposed method uses a non-linear stress-strain curve for the concrete and bilinear elastic-plastic relationship for reinforcement; equilibrium conditions at a sectional level to generate the strain energies along the beam. At the end of this article are shown three specific numerical examples with comparative, experimental (two tests) results with the excellent agreement and one calculation result with a great disagreement, by obtaining results of virtual principle method. With this method is avoiding the adoption of an unsure (EJ), as in the case of underestimating or overestimate initial flexural rigidity.
{"title":"Virtual Principle for Determination Initial Displacements of Reinforced Concrete and Prestressed Concrete (Overtop) Members","authors":"M. Balabušić","doi":"10.4236/ojce.2021.112015","DOIUrl":"https://doi.org/10.4236/ojce.2021.112015","url":null,"abstract":"Theoretical approach with analytical and numerical procedure for \u0000determination initial displacement of a reinforced and prestressed concrete \u0000members, simple and cantilever beams, loaded by axial forces and bending \u0000moments is proposed. It is based on the \u0000principle of minimum potential energy with equality of internal and \u0000external forces. The equations for strain internal energy have been derived, \u0000including compressed and tensile concrete and reinforcement. The energy equations of the external forces with axial flexural \u0000displacement effects have been derived from the assumed sinusoidal \u0000curve. The trapezoid rule is applied to integrate the segment strain energy. \u0000The proposed method uses a non-linear stress-strain curve for the concrete and bilinear elastic-plastic \u0000relationship for reinforcement; equilibrium conditions at a sectional level to \u0000generate the strain energies along the beam. At the end of this article are \u0000shown three specific numerical examples with comparative, experimental (two \u0000tests) results with the excellent agreement and one calculation result with a \u0000great disagreement, by obtaining results of virtual principle method. With \u0000this method is avoiding the adoption of an unsure (EJ), as in the case of \u0000underestimating or overestimate initial flexural rigidity.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134410448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.4236/ojce.2021.112014
W. Khatri, M. A. Mehthel, S. A. Ghamdi, Nezar Al Khalifa
Rubblization technique has been extensively used to repair the damaged concrete pavement and has proven successful in developed countries like the US and Europe. It has not been fully adopted in developing region like the Middle East and this paper presents the design and construction challenges posed while assessing damaged concrete runway in empty quarter of Saudi Arabia. A number of design options for repairs for runway pavement were considered and rubblization was chosen as a preferred option for repair. This paper includes the consideration for the assessment and adoption of the concrete rubblized modulus value using the falling weight deflectometer, optimization of the tests for the whole runway using the Heavy Weight Deflectometer HWD testing to replace pits, safely working around the utilities, reasonable assumption of drop height of the pavement and installation of utility conduits in the rubblized layer. Findings of the paper demonstrates resolving technical issues which are not very well covered in the Federal Aviation Authority (FAA) EB-66 such as the additional test strips, minimum areas of rubblization for assessment using test pits, drop in the height of concrete surface and fixing of utilities in rubblized pavement. The case study demonstrates that the rubblization can be successfully carried out in remote locations like empty quarter of Saudi Arabia with carefully carried out detailed site investigations, adopting correct assumed design rubblization modulus, quality control using HWD, protection of utilities while rubblizing and use of polymer modified asphalt for successful project deployment.
{"title":"Rubblization: A Practical, Cost Effective and Sustainable Option for Repairing Deteriorated Airfield Pavement in the Empty Quarter Desert of Saudi Arabia","authors":"W. Khatri, M. A. Mehthel, S. A. Ghamdi, Nezar Al Khalifa","doi":"10.4236/ojce.2021.112014","DOIUrl":"https://doi.org/10.4236/ojce.2021.112014","url":null,"abstract":"Rubblization technique has been extensively used to repair the damaged \u0000concrete pavement and has proven successful in developed countries like the US \u0000and Europe. It has not been fully adopted in developing region like the Middle \u0000East and this paper presents the design and construction challenges posed while \u0000assessing damaged concrete runway in empty quarter of Saudi Arabia. A number of design options for repairs for runway \u0000pavement were considered and rubblization was chosen as a preferred \u0000option for repair. This paper includes the consideration for the assessment and \u0000adoption of the concrete rubblized modulus value using the falling weight \u0000deflectometer, optimization of the tests for \u0000the whole runway using the Heavy Weight Deflectometer HWD testing to \u0000replace pits, safely working around the utilities, reasonable assumption of \u0000drop height of the pavement and installation of utility conduits in the \u0000rubblized layer. Findings of the paper demonstrates resolving technical \u0000issues which are not very well covered in the Federal Aviation Authority (FAA) \u0000EB-66 such as the additional test strips, minimum areas of rubblization for \u0000assessment using test pits, drop in the height of concrete surface and fixing \u0000of utilities in rubblized pavement. The case study demonstrates that the \u0000rubblization can be successfully carried out in remote locations like empty \u0000quarter of Saudi Arabia with carefully carried out detailed site \u0000investigations, adopting correct assumed \u0000design rubblization modulus, quality control using HWD, protection of \u0000utilities while rubblizing and use of polymer modified asphalt for successful \u0000project deployment.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"5 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130506051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.4236/OJCE.2021.112012
J. Garcia-Pérez, E. García-López
The reliability optimization process in earthquake engineering requires that the expected present value of the total cost is minimized, including the initial cost as well as the damage costs caused by earthquakes, which include indirect costs. One of these costs is concerned with how much society is willing to invest for preserving human life. Ethical principles, on which to base the assessment of this cost, are presented and discussed in this work. Individual and social values are analyzed. Finally, an optimal seismic design coefficient with the results obtained is calculated for a site with low seismicity.
{"title":"Ethical Principles Underlying the Assessment of Indirect Losses Due to Earthquakes","authors":"J. Garcia-Pérez, E. García-López","doi":"10.4236/OJCE.2021.112012","DOIUrl":"https://doi.org/10.4236/OJCE.2021.112012","url":null,"abstract":"The reliability optimization process in earthquake engineering requires that the expected present value of the total cost is minimized, including the initial cost as well as the damage costs caused by earthquakes, which include indirect costs. One of these costs is concerned with how much society is willing to invest for preserving human life. Ethical principles, on which to base the assessment of this cost, are presented and discussed in this work. Individual and social values are analyzed. Finally, an optimal seismic design coefficient with the results obtained is calculated for a site with low seismicity.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"343 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124241934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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