scholarly journals Analytical Design of Irregular Buildings founded on soft soil

2021 ◽  
Vol 1197 (1) ◽  
pp. 012015
Author(s):  
Abhishek Yadav ◽  
Shobhit Bhardwaj ◽  
Zenia Karam ◽  
Madhuri Kumari

Abstract In modern day, due to the need of unique architectural appearance or aesthetics of building, irregularities in mass, stiffness and symmetry may get disturbed, making the whole structure vulnerable to certain damages either minor or major. Some of the functional considerations of these structures are use of ground floor as car parking in residential buildings, use of basement as car parking in malls, etc. Seismic range is one the most important factors to be considered to analyze any irregular structure. In this study, the design of different G+6 structures having vertical regularity was done. These irregular structure models were compared with a regular G+6 structure having similar properties as other structures. For the designing and analysis of these structures, use of StaadPro software was done. It is one of the most used software, whenever it comes to the digital analysis of any structure. Different types of Vertical irregularities like mass irregularity, Vertical Setback Irregularity, Stiffness Irregularity (Discontinuous Column, Middle weak storey and Bottom Weak Storey) were considered for the analysis. The Seismic Zone for the structure is considered to be Delhi (Seismic Zone IV) with a Seismic Factor of 0.24. All the model structures were compared for the parameters of their Storey Drift and Storey Displacement. For irregular buildings though, certain damages/fatigue may be observed in some structures but the structures will not fail and will be serviceable for a long time with proper care. It was observed that the structures with stiffness irregularity showed the most increase in storey displacement and storey drift values.

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6684
Author(s):  
Miltiadis Zamparas ◽  
Grigorios L. Kyriakopoulos ◽  
Marios Drosos ◽  
Vasilis C. Kapsalis

The research objective of the study is the estimation of a novel low-cost composite material f-MB (Fe-modified bentonite) as a P and N adsorbent from wastewaters. Τhe present study aimed at examining the phosphate and ammonium removal efficiency from different types of wastewater using f-MB, by conducting bench-scale batch experiments to investigate its equilibrium characteristics and kinetics. The SEM analysis revealed that the platelets of bentonite in f-MB do not form normal bentonite sheets, but they have been restructured in a more compact formation with a great porosity. Regarding the sorption efficiencies (Qm), the maximum phosphate sorption efficiencies (Qm) calculated using the Langmuir model were 24.54, 25.09, 26.13, 24.28, and 23.21 mg/g, respectively, for a pH range of 5 to 9. In addition, the maximum NH4+-N adsorption capacities (Qm) calculated from the Langmuir model were 131.8, 145.7, 168.5, 156.7, and 159.6 mg/g, respectively, for a pH range from 5 to 9. Another important finding of this study is that f-MB can recover P from treated wastewater impacting on resource recovery and circular economy (CE). The modified clay f-MB performed the phosphate and ammonium recovery rates of 80% and 78.5%, respectively. Finally, f-MB can slowly release the largest proportion of phosphate and ammonium ions for a long time, thus extending the application of the f-MB material as a slow-release fertilizer and soil improver.


2021 ◽  
Vol 11 (23) ◽  
pp. 11141
Author(s):  
Tae-Woong Kong ◽  
Hyun-Min Yang ◽  
Han-Seung Lee ◽  
Chang-Bok Yoon

High fluidity concrete exhibits an excellent self-compacting property. However, the application of typical high-fluidity concrete is limited in the normal strength range (18~35 MPa) due to the large amount of binder. Therefore, it is important to solve these problems by adding a viscosity modifying agent (VMA) with a superplasticizer (PCE), which helps to improve the fluidity of the concrete. In addition, the rheology and stability of the concrete with VMA can be improved by preventing bleeding and segregation issues. Current studies focused on the physical phenomena of concrete such as the fluidity, rheological properties, and compressive strength of normal-strength, high-fluidity concrete (NSHFC) with different types of a polycarboxylate-based superplasticizer (NPCE). The obtained results suggested that the combinations of all-in-one polycarboxylate-based superplasticizers (NPCE) did not cause any cohesion or sedimentation even stored for a long time. The combination of three types of VMA showed the best fluidity (initial slump flow of 595~630 mm) without any segregation and bleeding, and the compressive strength at 28 days was also found to be the highest: 34–37 MPa. From these results, the combination of PCE (2.0%) + HPMC (0.3%) + WG (0.1%) + ST (0.1%) showed an 18% higher plastic viscosity and -4.4% lower yield stress than Plain.


2020 ◽  
Vol 156 ◽  
pp. 05026
Author(s):  
Fauzan ◽  
Afdhalul Ihsan ◽  
Mutia Putri Monika ◽  
Zev Al Jauhari

The amount of potential investment in Padang City, Indonesia since 2017 attracted many investors to contribute to the city. One of the investments is a 12-story hotel that will be constructed in By Pass Street of the city. The hotel is located in a high seismic zone area, so the seismic base isolation has been proposed to be used in the hotel building. The main aim of using a seismic base isolation device is to reduce the inertia forces introduced in the structure due to earthquakes by shifting the fundamental period of the structure out of dangerous resonance range and concentration of the deformation demand at the isolation system. An analytical study on the Reinforced Concrete (RC) hotel building with and without rubber bearing (RB) base isolation is carried out using the response spectrum and time history analysis methods. The results show that internal forces and inter-story drift of the building with high damping rubber bearing (HDRB) are lower than that of the fixed base with a remarkable margin. From this study, it is recommended to use the HDRB base isolation for medium and high rise buildings with soft soil in Padang City, Indonesia.


2019 ◽  
Vol 5 ◽  
pp. 153-164
Author(s):  
Sagar Bista ◽  
Sagar Airee ◽  
Shikshya Dhital ◽  
Srijan Poudel ◽  
Sujan Neupane

Concrete is weak in tension, hence some measures must be adopted to overcome this deficiency as well as to enhance physical and other mechanical properties but in more convenient and economical method. Through many research from the past, it has been observed that addition of different types of fibres has been more effective for this purpose. This report presents the work undertaken to study the effect of steel and hay fibre on normal cement concrete of M-15 Grade on the basis of its mechanical properties which include compressive and tensile strength test and slump test as well. Although hay fibres are abundantly available in Nepal, no research have been popularly conducted here regarding the use of hay fibres in concrete and the changes brought by it on concrete’s mechanical properties. Experiments were conducted on concrete cubes and cylinders of standard sizes with addition of various percentages of steel and hay fibres i.e. 0.5%, 1% and 1.5% by weight of cement and results were compared with those of normal cement concrete of M-15 Grade. For each percentage of steel and hay fibre added in concrete, six cubes and six cylinders were tested for their respective mechanical properties at curing periods of 14 and 28 days. The results obtained show us that the optimum content of fibre to be added to M-15 grade of concrete is 0.5% steel fibre for compression and 0.5% hay fibre content for tension by weight of cement. Also, addition of steel and hay fibres enhanced the binding properties, micro cracking control and imparted ductility. In addition to this, two residential buildings were modeled in SAP software, one with normal concrete and other with concrete containing 0.5% steel fibre. Difference in reinforcement requirements in each building was computed from SAP analysis and it was found that 489.736 Kg of reinforcement could be substituted by 158.036 kg of steel fibres and decrease in materials cost of building with 0.5% steel fibre reinforced concrete was found to be Rs. 32,100.


2018 ◽  
Vol 1145 ◽  
pp. 8-16 ◽  
Author(s):  
Jing Rui Guo ◽  
Xian Chang Zheng ◽  
Ji Qing Zhang ◽  
Zhi Meng Zhao

The EVP model is an available method to apply to the vertical settlement of soft soil consolidation calculation and analysis. Compared with Visco-Plasticity model, it shows more consistent with the actual stress conditions of the soil. In this paper, We have extracted soil samples in BinHai garden for assay. Then through the comparison with calculating results and a long-time engineering monitoring in BinHai garden soft soil area, a feasibility EVP model study on the vertical settlement in soft soil area is peoposed. Further a consequent sedimentation forecast was made according with the EVP model calculation. In the end, the settlement influence from creep was analyzed through one-dimensional consolidation theory.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Nu Nguyen Thi ◽  
Bui Truong Son ◽  
Do Minh Ngoc

The horizontal coefficient of consolidation is the most important parameter for designing the improvement of soil soft by prefabricated vertical drains (PVDs) combined with surcharge and vacuum preloading. This paper presents the experimental study on the horizontal coefficient of consolidation (ch) of some soft soils distributed in Vietnam. The ch value was determined by the laboratory test and CPTu dissipation test. The laboratory tests included the Rowe consolidation cell test and constant rate of strain consolidation with radial drainage test. Two types of consolidation laboratory tests were performed. The experimental results indicated that the ch value is always larger than the vertical coefficient of consolidation of soil (cv). The ratio of ch/cv depends on the consolidated pressure, type of soil, and the anisotropy of soil. The ratio of ch/cv is different in different types of soft soil in Vietnam. In the normally consolidated state, the ch/cv ratio ranges from 1.35 to 10.59. It was necessary to choose the ch value at the consolidated stress level for calculating the PVD spacing.


2018 ◽  
Vol 49 (2) ◽  
pp. 109-116
Author(s):  
Gonca Akcaer ◽  
Asena Soyluk

In this study, on airport terminal building design, passing long span beams and the concept of biomimesis have been the design criteria; the use of a steel structure has been examined for supporting the design form. In the airport terminal building, steel roof types in smooth surfaced, single curved-arciform, and double-curved wave forms have been designed. The three different types of steel frame roof model have been designed with the forms frequently used within the scope of the biomimesis concept and provide a covering shaped like a bird's nest, bird wing and bubble. Dynamic analysis of the three different roof forms is according to the first-degree seismic zone and Z4 local ground class. As a result, in the long-span design criterion, the aesthetics and function influence each other and change the building's behaviour.


2006 ◽  
Vol 9 (4) ◽  
pp. 591-596 ◽  
Author(s):  
Aldur W. Eriksson ◽  
Johan Fellman

AbstractTemporal variations in the stillbirth rate among singletons, twins and triplets in Sweden between 1869 and 1967 were studied. Both among single and multiple births there were marked secular decreasing trends in the stillbirth rates. Based on our long time series since 1869, this study confirms that among twins and triplets the stillbirth rate was higher among same-sexed than among opposite-sexed sets. Comparisons between the stillbirth rates among twin births in urban and rural regions indicate higher stillbirth rates in rural areas. In addition, the stillbirth rates among twins of unmarried mothers were higher than those of twins of married mothers. These findings also hold for both same-sexed and opposite-sexed twin pairs. Analyses of the stillbirth rates for singletons and for different types of twins indicate that up to 1950 the risk of stillbirth among males was almost constantly between 15% to 20% higher than among females. After that the difference in the risk decreased. Comparisons with other populations were performed.


Sign in / Sign up

Export Citation Format

Share Document