Recent Developments in Structural Engineering, Volume 3

Inhaltsverzeichnis

1. Frontmatter

2. Sloshing Phenomena in Square Water Tanks with Internal Obstructions Using Fluid Dynamics

   Muhammed Zain Kangda, Rohan G. Raikar, Venkatesh Wadki

   Abstract

   The present study examines the sloshing behavior of water filled in square shaped ground supported liquid storage tanks. The study validates the empirical equations available to determine the sloshing parameters namely sloshing frequency and sloshing mass in the first three modes for square tanks without obstruction. Finite element approach is adopted to investigate the effect of centrally placed obstruction in square shaped ground supported water tanks. The FLUID80 element is used to model the liquid with the help of ANSYS mechanical APDL program to evaluate the performance of various configurations of water tanks. The study evaluates the sloshing behavior under the free vibration analysis for four square tanks of dimensions 2, 4, 6 and 8 m. The height to length ratio of the square tanks is varied from 0.1 to 2 in the increment of 0.1. The study develops graphs of sloshing parameters for square tanks with centrally placed obstruction in the first three modes of vibration. The study finally concludes that the central obstruction limits the sloshing mass excited for square tank configurations. The results show the complex nature of sloshing parameters due to the presence of a central rigid square obstruction. The sloshing mass excited decreases due to presence of a central obstruction in the first mode. However, in the second and third mode the presence of obstruction results in the increase in the mass excited as compared to that observed for tank without obstruction condition.

3. Comparison of Strength of the Unreinforced Masonry Prisms with Different Masonry Bonds

   Pranoy Debnath, Sekhar Chandra Dutta

   Abstract

   Unreinforced masonry (URM) structures are among the oldest structural methods used in various parts of the earth. Many existing URM buildings have been standing for years and must be considered valuable architectural heritage. The actual reasons behind the undesirable seismic behaviour of the URM structures are identified as inadequate lateral load-resisting elements, weak load-bearing walls, lack of integrity of the structural elements etc. The lack of knowledge in constructing the URM buildings is also a cause of failure. As a result, protecting these structures against various loads is very essential. Surprisingly, different types of masonry brick bonds are used for constructing URM buildings without knowing their load-carrying capacity all over the world. So, in this paper, an effort has been made to evaluate the capacity of four different types of URM brick bonds mentioned in standard Indian codes. The compressive load-carrying capacity has been checked here. Further, in-plane and out-of-plane load-carrying capacity is also tested experimentally. The experimental results show that the URM walls made with English and Flemish bonds perform better. It is shown that the capacity increased by about 18–20% in all the above two cases due to proper bonding between the brick elements. Ductility is expected to increase in the same order. So, this bonding approach enhances the capacity of masonry structures should be practiced, which has been ignored for a very long time. This approach can be adopted by any person willing to construct the URM structures without any special knowledge and without increasing any cost.

4. A Novel Computationally Efficient Procedure for the Nonlinear Instantaneous Analysis of Composite Flexural Members Within Serviceability Limit

   M. A. Modi, K. A. Patel, Sandeep Chaudhary

   Abstract

   Steel–concrete composite flexural members are steel girders and concrete slabs connected by shear connectors at their interface. These members are gaining popularity due to their high span-to-depth ratio and ease of construction. But these members are slender and hence vulnerable to deflection criteria. As these members consist of concrete, they will be affected by cracking and tension stiffening at instantaneous loading within the serviceability limit. For this purpose, it is required to develop a procedure that takes into account the cracking and tension-stiffening effects. Therefore, a novel computationally efficient procedure has been proposed to account for the above effects in the composite flexural members subjected to service load for use in everyday design. At the element level, the procedure is analytical, and at the structural level, it is numerical. To simulate cracking, an ingenious cracked span-length two-noded beam element with two cracked zones and one uncracked zone was used. The tension stiffening is considered in the cracked zone to include the tensile strength of the uncracked concrete portion between two cracks. Average tension stiffening characteristics for cracked zones are determined to maintain the analytical nature of the procedure at the element level. The procedure resulted in both deflections and redistributed moments. The developed procedure has been validated by comparing the results from the finite element model. Since there is no discretization required along and across the members, the procedure would lead to a drastic reduction in computational time in the case of continuous composite beams.

5. Blast Loading Behaviour of RCC Structure

   Vrushali Shivaji Jagtap, Archana Girish Tanawade

   Abstract

   There has been a surge in demand for blast resistant architecture for significant buildings like hospitals, government buildings, etc. due to the fear of conflict increasing globally. The pressure created on a structure as a result of an explosion is extremely high and lasts for a very little period of time, meaning the impact on the building is highly severe and can result in significant structural damage. Significant structures need to be built in a way that they can withstand those intense pressures without suffering any major collapse. Blast loads are estimated in accordance with the steps outlined in IS 4991. Pressure intensity from IS 4991 has been calculated and converted to point loads acting at each level as per the distance from the blast source. The response spectrum analysis is also performed for seismic loading along with blast loads and parameters such as maximum lateral displacement, maximum story drift ratio, time period, maximum over-turning moment etc. are compared to assist the performance of the building. Also the blast load intensity has been varied as well as the standoff distance to estimate the effect of blast loads at various standoff distances and intensities. Expected outcomes from this project will be to understand the effect of accidental blast loading at some distance from the building and after analyzing the above cases some remedies for reducing the effects of blast loads by introducing shear walls and composite steel-RCC columns of the building has been suggested. The structural analysis is performed in finite element software i.e. ETABS and SAP2000.

6. Effect of Sodium Hydroxide Concentration and Alkaline Solution Absorption on Performance of Lightweight Geopolymer Concrete

   Rohit Rawat, Dinakar Pasla

   Abstract

   Cement production needs a significant energy content, needs several natural reserves including limestone, clay, and water, and is a significant contributor to greenhouse gas emissions. After replacing cement as a binder with by-products of industry like grass granulated blast furnace slag (GGBS) and fly ash (FA), they show good mechanical and durability properties. Total cement replacement with these by-products needs alkali-activated solutions (combination of sodium hydroxide (NH) and sodium silicate (NS)) to activate the reaction process and produce the final product called geopolymer concrete (GC). This study uses sintered fly ash aggregate (SFA) as coarse aggregate and sand as fine aggregate, with a mixture of FA and GGBS, to produce lightweight geopolymer concrete (LWGPC). An investigation has been carried out to determine the adequate solution absorption condition and molarity of NH solution so that LWGPC can achieve optimal compressive strength. Samples were prepared with different solution absorption conditions and, after that, with different molar ratios of NH. Samples were cured in ambient conditions. Compressive strengths (CS) of 3, 7, 28, and 56 days have been determined for the alkali-activated solution to the binder of 0.5, NS/NH 1.5, and a solution content of 207.5 kg/m³. Fresh density was obtained below 2000 kg/m³ for all the samples. A maximum CS of 42 MPa was obtained for 30 min solution absorption and a 12 molar solution of NH. All the LWGPCs satisfy criteria for structural lightweight concrete and can be acceptable for building construction purposes (CS > 17 MPa). Therefore, this proposed mixing using the given proportions can be used to design LWGPC.

7. Performance Evaluation of Base Isolated and Fixed Base Building

   P. N. Panda, R. Selot, A. Chakrabarti, V. Prakash

   Abstract

   Earthquakes can lead to significant damage in buildings. The extent of this damage is directly proportional to Inter-Storey Drift (ISD). Base Isolation (BI) and Concentric Braced Frames (CBF) are two of the most common systems that are used to limit ISD in buildings. This research is divided into two sections. In Section 2, cost analysis is done for BI and CBF buildings by designing them for MCE (Maximum Considered Earthquakes) and medium soil conditions as per the design guidelines of Indian and American codes. In Section 3, Non-Linear Time History Analysis (NLTHA) is executed to assess the performance of both the building model on their ability to minimize the ISD (post-earthquake importance) for three ground motions corresponding to medium soil condition. Conventional diagonal cross (“X”) braces have been considered in the CBF system. Standard properties of Lead Rubber Bearing (LRB) have been used for isolators. Two steel buildings (one each for BI and CBF) have been modeled in SAP 2000, and then both buildings are compared based on cost and ISD. Finally, concluding remarks are given for the best possible system in Earthquake Resistance Design of structures (EQRD).

8. Experimental Analysis of Traditional Wooden Joints

   Survesh Chetival, Sanjay Chikermane

   Abstract

   In the India Himalayan region, kath–kuni construction style is a centuries old, seismic resilient, construction system. In this system dry stone masonry with the combination of wooden beams and wooden connection is used. Earthquake resistance and ductility in these type of systems is found due to friction capacity in between layers and wooden connections. The connection in between wooden members are provided as a maanwi which is a dovetail type of connection and kadil which is a dowel type of connection. In this study, a separate experimental study has been done to understand behaviour of joints in historical building style. The joints were made of different sizes and were subjected to lateral loading condition. Experimental study was conducted to find out the coefficient of friction (μ) for different surface condition. The coefficient of friction found out to be varying in between 0.32 and 0.81 for mentioned conditions. Capacity of kadil, maanwi and bond strength were determined.

9. Effects on Compressive Strength and Mass Loss of Concrete Containing Fly Ash and GGFS Subjected to Sea Water Exposure Conditions

   Rahul Shah, Nikunj Pitroda, J. D. Rathod

   Abstract

   Construction and maintenance of Reinforced concrete structures near to marine environment are always being challenging to Engineering community keeping durability at a center. The sea salts present in sea water and air, gradually attack concrete and penetrate into body of the concrete structure. The leachable compounds tend to form expansive products and ultimately reduce the mass and compressive strength of the concrete. Delamination further exposes the concrete to chloride attack which in turn increases risk of reinforcement corrosion. The coastal area within few miles of the coast line and off shore structures remain in contact with marine salts present in form of airborne salts or saltwater or both. The physical effects like disintegration, mass loss and expansion etc., if addressed properly, the long term durability issues may be further diluted or may be addressed easily. Mix design, use of supplementary materials and other quality control measure play vital role in preventing physical effects on concrete. The present study examines the physical effects of suphate attack on concrete containing different proportion of fly ash (10, 20, 30%) and GGBS (20, 30, 40%) with M40 and M50 grade of concrete with continuous immersion in sea water conditions and wetting drying cycles. The effects of loss in compressive strength and mass loss is monitored and presented in this paper. The use of GGBS and Fly ash found out to be more effective in continuous immersion conditions compared to wetting drying conditions. Effectiveness and optimum dose of fly ash and GGBS in concrete for experimental conditions are also discussed.

10. A Comparative Study of Carbon and Stainless Steel Flat Oval Hollow Section Subjected to Pure Torsion

    Thounaojam Bidyaraj Singh, Khwairakpam Sachidananda

    Abstract

    The study shows the numerical investigation on flat oval hollow section members of cold-formed carbon steel and lean duplex stainless steel (LDSS) subjected under torsional loading using the finite element software, Abaqus. Parametric studies of the flat oval section have been performed for various slenderness ranging from slender to stocky sections. The flat-oval member length has been considered as three times that of the flat length of the member cross-section. On the basis of the finite element analyses, it can be observed that the torsional capacity of the LDSS section has higher capacity in comparison with the carbon steel in the ranges of 70–100% as thickness varies from 3 to 20 mm, even though the variation in the yield stress is around 87%. There is a linear increase of torsional capacity as the thickness increases for both the carbon and stainless steel but the stiffness of stainless steel is higher. The torsional capacity of the member decreases with an increase in the slenderness ratio of the member cross-section.

11. A Parametric Study on the In-Plane Poisson’s Ratio of Honeycomb Cellular Solids

    Shubham Sharma, Anurag Gupta, Rajib Chowdhury

    Abstract

    The study of the Poisson’s ratio constitutes a crucial aspect of materials science, as it is directly related to the deformation behavior of a material when subjected to stress. The investigation of Poisson's ratio in cellular solids holds immense significance, especially in the context of mechanical applications. Understanding their Poisson's ratio deepens the knowledge of their deformation properties and paves the way for revolutionary advancements in various engineering applications. This investigation focuses explicitly on examining the Poisson’s ratio of two types of cellular solids, namely, hexagonal and re-entrant honeycomb structures. The latter is a unique cellular material with a negative Poisson’s ratio and is commonly referred to as an auxetic structure. In this study, we explore how changes in the microstructure of the cellular solids, including modifications in the cell wall thickness and angle, affect the Poisson’s ratio. This study revealed a strong dependency of the Poisson’s ratio on the microstructure of the cellular solids, with the re-entrant honeycomb structure exhibiting a negative Poisson’s ratio than the hexagonal structure. By shedding light on Poisson's ratio behavior of these cellular structures, we can provide valuable insights that have important implications for developing novel lightweight materials, particularly in aerospace applications, where high strength and low weight are critical.

12. A Comparative Study of Peak Factor Prediction Models for Aerodynamic Loading on an Anticlastic Conical Tensile Membrane Structure

    Budhaditya De, Ajay Kumar, Sudib K. Mishra

    Abstract

    In this paper, the assessment of peak factors for aerodynamic loading on an anticlastic conical tensile membrane structure (TMS) is carried out along with a comparative study of several prediction models. The Unsteady Reynolds-Averaged-Navier–Stokes (URANS) based CFD simulations of a turbulent boundary layer around the TMS are used to obtain the time-varying aerodynamic loading (in the form of wind pressure coefficients) and associated peak factors on several representative locations on the TMS surface. The statistical moments of skewness and excess kurtosis are employed to categorize these locations into Gaussian and non-Gaussian regions. It is observed that points near the corners and the edges from where the flow separates have prominent non-gaussian behaviour with higher peak factors. The observed peak factors are compared with those from several prediction models namely the Davenport, Modified Hermite, Translated Peak Process (TPP), and Liu’s models. Root Mean Squared (RMS) errors are calculated for each case to quantify the extent of difference between the observed and predicted peak factors and it is conclusive that the Modified Hermite model predicts the best whereas, the Davenport model has the poorest prediction capability.

13. Optimal PFPI Based Passive Control Strategy for Seismic Control of Phase-II Benchmark Cable Stayed Bridge

    Susmita Swain, Purnachandra Saha

    Abstract

    The Phase-II benchmark cable-stayed bridge problem evaluates the effectiveness of the friction pendulum system (FPS) and the polynomial friction pendulum isolator (PFPI) in reducing seismic effects. By varying the isolator parameters, this study evaluates their performance under various loads and incident angles. When these isolators are deployed, there is a considerable reduction in base shear, overturning moments, and seismic responses. MATLAB and Newmark's step-by-step integration approach are used for seismic response analysis. A comparison of the seismic responses of the isolated benchmark bridge reveals that PFPI outperforms FPS. The effect of the isolation time period on structure reaction is determined by the individual isolator type and the earthquake ground motion parameters. This research provides useful insights into the behavior of FPS and PFPI systems, emphasizing the PFPI’s potential as an effective seismic control option for cable-stayed bridges.

14. Response Spectrum Analysis for Soft Storey Determination

    Peeyush Sunil Aherkar, M. M. Murudi, Kshitija Nadgouda

    Abstract

    The construction of soft storey buildings in India has increased for fulfilling the need of parking and other commercial spaces. A soft storey may be present at any floor level in the building. The provision of soft storeys at different floor levels in a building result in reduced stiffness of lateral load resisting elements due to absence of masonry infills.

    Based on literature review it was found that limited study has been carried out about new provisions of IS 1893:2016. The focus of this study was to investigate the effect of soft storey and to determine actual magnification factor required for design of a case study. The system was modelled using two editions of IS 1893, one published in 2002 and second in 2016. The presence of infill walls was modelled in ETABS by using an equivalent diagonal strut as per IS 1893:2016 (Criteria for earthquake resistant design of structures. Part 1 General Provisions and Buildings. Bureau of Indian Standards, New Delhi, India, 2016 [1]), whereas there was no such provision in 2002 (Criteria for earthquake resistant design of structures. Part 1 General Provisions and Buildings. Bureau of Indian Standards, New Delhi, India, 2002 [2]). In the present study the fifteen-storey structure was analyzed by varying the level at which soft storey was provided. The values of storey stiffness, displacement, drift and time period were calculated using the two editions of IS 1893 (Criteria for earthquake resistant design of structures. Part 1 General Provisions and Buildings. Bureau of Indian Standards, New Delhi, India, 2016 [1], Criteria for earthquake resistant design of structures. Part 1 General Provisions and Buildings. Bureau of Indian Standards, New Delhi, India, 2002 [2]) and then compared. The magnification factors required for design of soft storey elements were also evaluated using response spectrum analysis and the significance of diagonal strut method was highlighted.

    The present study concluded that modelling the infill walls as equivalent diagonal strut is conservative. The presence of infill walls as per 2016 code resulted in reduced magnification factors required for design of soft storey elements.

15. Enhancing Mechanical Properties of Concrete Using Garment Waste Fibers and Fly Ash

    Rokibul Hossain Titu, Khaliqul Bari

    Abstract

    The world’s growing population has resulted in an increase in the production of garments, which in turn has led to a rise in garment waste. This study aims to investigate the potential use of garment waste fibers (GWF) in concrete production, along with 20% fly ash as a replacement of cement. The effects of fly ash and garments waste fibers on the compressive and tensile strength of concrete specimens were evaluated through testing at 7 days, 28 days, and 90 days. Results showed that the compressive strength of specimens without fibers or fly ash increased over time, attributed to the formation of calcium-silicate-hydrate (C-S–H) and improved molecular bonding. However, the addition of garments fibers in proportions of 0.5% and 1% of concrete volume resulted in a decrease in compressive strength during the early curing stages. The inclusion of fly ash did not significantly affect strength in the shorter testing periods but positively influenced long-term strength at 90 days. Similarly, the tensile strength of the specimens increased with time, with higher values observed at 28 days and 90 days compared to 7 days. The presence of fibers contributed to additional tensile strength, with a more effect observed at a fiber ratio of 1%. While the addition of fly ash had limited influence on tensile strength in the shorter testing periods, it positively impacted the strength at 90 days. These findings suggest optimized combination of GWF and fly ash content can lead to improved mechanical proerties of concrete in the long run.

16. A Study on the Hysteretic Behaviour of Combined Metallic Yielding Dampers Under Cyclic Load Using Finite Element Software

    Bajrabahu D. N. Deo, Sanjeev Kumar, Romanbabu M. Oinam

    Abstract

    The combined metallic yielding device (CMD) is a passive yielding damping device with stable hysteresis, high stiffness, ductility, and energy dissipation capacity. CMD is commonly used in the seismic retrofitting of structures to reduce the seismic response and improve structural performance. The working principle of CMD is the combination of flexural and shear mechanisms under lateral loading. The primary components of CMD are two base plates, two flexural plates, one shear plate, and two shear tabs. The shear plate is attached to the base plate through shear tabs. The connection between the shear plate and shear tab could be welding or bolting. Both types of connection show a different mode of hysteresis response. Welding connection shows high initial stiffness with limited ductility due to premature tearing of the plate. In contrast, bolt connection shows lower initial stiffness and higher ductility and energy dissipation due to its tendency to delay the failure of thin web (shear) plates through bearing/tearing under in-plane lateral loading and distribute the bearing stresses at sufficient locations. Considering these facts, in this study, two different types of CMDs are taken into account, where the shear plates and shear tabs are connected by bolts and welding. To investigate the hysteretic response, load carrying capacity, and drift capacity, numerical models are created using Finite Element software. The numerical findings are compared with the experimental findings. This comparison indicates that connections between the shear plate and shear tab influence the performance of CMD. Overall, the study demonstrates the effectiveness of CMD and provides valuable insights into the design of CMDs.

17. Deep Learning Potential for Characterization in Ultrasonic Crack in Concrete Structure: A Review

    Abhishek Sharma, Surendra Beniwal

    Abstract

    The ultrasonic technique is one of the most widely used techniques in Non-destructive Testing to detect damage in civil engineering structures. It is a popular method of Non-destructive Evaluation (NDE) due to its versatility, high sensitivity on most materials, and ability to extract information about the location and type of defects. The applications of Deep Learning (DL) algorithms in ultrasonic inspection attracted much attention in recent years due to their superior ability to recognize damage and flaws in civil engineering structures. The initial section of the paper introduces the DL algorithms employed in the ultrasonic crack analysis. It then proceeds to examine the latest developments in autonomous ultrasonic NDE facilitated by DL techniques. Moreover, the paper also reviews the applications of DL to defect-related problems, such as defect detection and classification. This review paper focuses on exploring the use of DL techniques for ultrasonic crack characterization, with an emphasis on quantifying the associated uncertainty.

18. Effect of Toothing Schemes and Tooth Sizes on the Performance of Confined Brick Masonry Walls: A Parametric Study

    A. N. Shandilya, Vijay Kumar, A. Haldar, S. Mandal

    Abstract

    Confined brick masonry (CBM) employs in-situ cast reinforced concrete (RC) elements around small-height wall segments. The poured concrete fills gaps, covers protruding bars, and tightly secures the masonry walls through toothing at corners and openings. This secure connection is achieved through “toothing” in the masonry walls, strategically located at the corners and junctions. This study used numerical simulations in ABAQUS to determine the behaviour of CBM wall panels with different toothing schemes and tooth details during a seismic event. A non-linear finite element macro-model is used for the parametric study on CBM walls. The study found that machine-made hollow units with toothing improved lateral capacity by 12.0% more than the hand-made scheme and 12.20% higher than the toothing scheme with horizontal reinforcement. Furthermore, investigating different tooth sizes for the CBM wall showed that varying protruding brick’s vertical and horizontal spacing can significantly improve seismic performance. Specifically, the study found that closer vertical spacing, i.e., 100 mm of protruding bricks, provides 17.8% higher lateral capacity than the wall with a vertical projection of 200 mm, resulting in better seismic performance of CBM walls. These findings likely have significant implications for designing and constructing CBM walls in earthquake-prone regions since optimising toothing details can enhance seismic performance and increase overall safety.