scholarly journals Unexpectedly two storied tin shed collapse: A case study of urban hazard in Dhaka city, Bangladesh

2018 ◽  
Vol 56 (1) ◽  
pp. 43-48
Author(s):  
Mohammad Feruj Alam ◽  
Munir Hossain ◽  
Md Azahar Hossain
Keyword(s):  
Construction Materials ◽  
Shallow Foundation ◽  
Silty Sand ◽  
Dry Density ◽  
Dhaka City ◽  
Deep Foundation ◽  
Filling Materials ◽  
Clayey Silt ◽  
Limit Test ◽  
Urban Hazard

The study has been carried out for an urban hazard analyses to find out the engineering geological characteristics of subsurface sediments and causes of two storied tin shed unexpectedly and suddenly collapsed and submerged in Rampura valley, Dhaka city, Bangladesh on the 15 April, 2015. Total 12 people were spot died due to collapsed tin shed. The area is covered by valley and this valley is composed of organic material, clayey silt, silty sand and sandy silt. Atterberg limit test indicates that the sediments are slightly plastic and low compressibility inorganic silts. Specific gravity of the sediments varies from 2.66 to 2.68, natural moisture content about 34.5%, dry density about 1.37 gm/cc, wet density about 1.84 gm/cc and unconfined compression strength about 45.9 Kpa. From this result, it reveals that shallow foundation is not suitable for the study area but deep foundation particularly pile foundation would be required. Five major possible causes have been identified for this incident, these are (1) presence of a valley and valley deposits, (2) very soft organic clay and soft slightly plastic clayey silt, (3) poor quality construction materials of shed and shallow foundation pillar, (4) overloaded by inhabitants with their usable items, and (5) filled up asides of the valley by filling materials which pressurized the pillar of the shed. Due to push or additional side pressure by filling materials to the foundation pillar, the pillar was moved and imbalanced the total shed and finally shed was suddenly subsided and collapsed by uniform settlement. Finally, it can be concluded that geological and engineering - geological study must be carried out for an urban hazard analyses in Rampura valley area as well as other valley areas in Dhaka city for future plan of urbanization and avoiding this type of urban hazard.  

scholarly journals An investigation into the cause of road failure along Sagamu-Papalanto highway southwestern Nigeria

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ubido Oyem Emmanuel ◽  
Igwe Ogbonnaya ◽  
Ukah Bernadette Uche
Keyword(s):  
Construction Materials ◽  
Road Construction ◽  
Linear Shrinkage ◽  
Liquid Limit ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Southwestern Nigeria ◽  
Low Resistivity ◽  
The Road ◽  
Cause Of Failure

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.

scholarly journals Foundation Piles—A New Feature for Concrete 3D Printers

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2545
Author(s):  
Marcin Hoffmann ◽  
Krzysztof Żarkiewicz ◽  
Adam Zieliński ◽  
Szymon Skibicki ◽  
Łukasz Marchewka
Keyword(s):  
3D Printing ◽  
Rapid Development ◽  
Construction Materials ◽  
Shallow Foundation ◽  
Soil Reinforcement ◽  
3D Printer ◽  
Permanent Formwork ◽  
3D Printers ◽  
New Feature ◽  
The Cost

Foundation piles that are made by concrete 3D printers constitute a new alternative way of founding buildings constructed using incremental technology. We are currently observing very rapid development of incremental technology for the construction industry. The systems that are used for 3D printing with the application of construction materials make it possible to form permanent formwork for strip foundations, construct load-bearing walls and partition walls, and prefabricate elements, such as stairs, lintels, and ceilings. 3D printing systems do not offer soil reinforcement by making piles. The paper presents the possibility of making concrete foundation piles in laboratory conditions using a concrete 3D printer. The paper shows the tools and procedure for pile pumping. An experiment for measuring pile bearing capacity is described and an example of a pile deployment model under a foundation is described. The results of the tests and analytical calculations have shown that the displacement piles demonstrate less settlement when compared to the analysed shallow foundation. The authors indicate that it is possible to replace the shallow foundation with a series of piles combined with a printed wall without locally widening it. This type of foundation can be used for the foundation of low-rise buildings, such as detached houses. Estimated calculations have shown that the possibility of making foundation piles by a 3D printer will reduce the cost of making foundations by shortening the time of execution of works and reducing the consumption of construction materials.

scholarly journals Evaluation of Strength Properties of Subgrade Materials Stabilized with Bio-Enzyme

2020 ◽  
Vol 5 (5) ◽  
pp. 607-610
Author(s):  
Bamidele S. Raheem ◽  
G. F. Oladiran ◽  
D. A. Oke ◽  
S. A. Musa
Keyword(s):  
Laboratory Experiments ◽  
Strength Properties ◽  
Dry Density ◽  
Sand Sample ◽  
Stabilizing Agent ◽  
Filling Materials ◽  
Base Materials ◽  
Long Term Effect ◽  
Enzyme Dosage

In the recent studies many chemical have been emerged and used as stabilizing agent. One of such chemical (Bio-enzyme) was used in this study as a stabilizing agent. Bio-enzyme is prepared locally from fermented vegetable and fruits waste. These products are natural, nontoxic, non-corrosive, nonflammable liquid and environmentally harmless. In this research, Bio-enzyme was prepared and used in varying proportion to stabilize laterite samples collected from different locations. Detailed laboratory experiments (Classification tests and CBR) were conducted to evaluate the effects of Bio-enzyme at varying dosage after 24 hours of curing of specimens. The percentage passing through sieve No. 200(75 micron) was less than 35%., according to ASHTO and clause 6201 of Federal Ministry of Works and Housing (F.M.W & H) Specification Requirements, sample A is (A-2-5), sample B is (A-2-4) while sample C is classified as A-2-6 and they are silty or clayed gravel and sand. Sample A is a good subgrade, subbase or base materials based on highest CBR values (at 20% bio-enzyme dosage, Sample A (102.50%) and sample B (69.40%) & at 10% sample C (33.2%). Sample B can also be used as subgrade or subbase materials where light traffic is considered and sample C is suitable as filling materials as evident in their CBR value. It has been observed that Bio-enzyme treated soil shows significant improvement in terms of the dry density and CBR value. Presence of Bio-enzyme in the soil samples led to increase in the C.B.R by 10-20% as compared to the control). However, it is recommended that assumption should not be made that Bio-enzyme is considered suitable for all type of soil and long term effect of it should also be examined.

scholarly journals Clay Minerals Variations in Quaternary Sediments of Basrah City-Iraq

2017 ◽  
Vol 6 (2) ◽  
pp. 41
Author(s):  
Mohanad Hamid Al-Jaberi
Keyword(s):  
Clay Minerals ◽  
Mineralogical Composition ◽  
Silty Sand ◽  
Recent Sediment ◽  
Quaternary Sediments ◽  
Marine Transgression ◽  
Fine Grain ◽  
Clayey Silt ◽  
Marine Facies ◽  
Mixed Layers

Mineralogical and chemical analysis of two well cutting in quaternary sediments at Basrah city. This study have been focused on the quaternary clay minerals variations which give a clear indication to marine transgression and or / regression in Hammar formation. Kaolinite, Illite, Palygoreskite, Illite-Palygorestike mixed layer, Chlorite, Montmorillonite, Vermiculte, and mixed layers of Illite- Smectite are the most quantitatively important phyllosilicates in soil studies in both boreholes. The mineralogical composition of cutting sediments shows significant variability in the different size fractions and depth distribution. Chlorite and kaolinite minerals were increase in the fine grain size especially in the clayey silt, whereas montmoriolllinite and vermiculite minerals were increase in coarse grains especially in silty sand texture. Kaolinite decrease in abundance with depth, which give indicative of a transition from non-marine in quaternary recent sediment ( fresh or brackish water silt) to marine facies in quaternary Hammar formation ( marine shelly silt) during last transgression of quaternary. Palygoreskite mineral percentages increasing at depths 27 and 28 meter , after decreased at 30, 32, 35 , and 40 m respectively , which give data indication that early quaternary marine transgression happened in 32m , and center of quaternary marine transgression detected in 27 and 28 meters , while late marine transgression detected in 17 m , and all of these represent by Hammar formation. Soil ageing also caused to downward increase of montmorillonite suggest to climate became more arid during the early quaternary. Variations ratio of montmorillonite versus kaolinite can be indicated to climatic fluctuation. Illite-Semectite featured indicates changes in both sediment source and paleoclimate. Illite transformation for Illite-Palygoreskite mixed layers with ageing. Vermiculite has strong susceptibility to increase with age. SiO₂, Al₂O₃, CaO, MgO, K₂O, and Fe₂O₃ were the major oxides that identified in present study and used as indicated of clay minerals in studied sediments.

Evaluation of Suitability of Red Clay from Selected Areas of Gercus Formation, Sulaimaniyah, North Iraq, for the Construction of Embankment Dams

2021 ◽  
pp. 3417-3427
Author(s):  
Amera I. Hussain Hussain ◽  
Ibraheem I. Ibraheem
Keyword(s):  
Ph Value ◽  
Soil Classification ◽  
Liquid Limit ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Red Clay ◽  
Embankment Dams ◽  
Filling Materials ◽  
The North ◽  
Geotechnical Assessment

      In this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications.      The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges.  The results of the plasticity limits test showed that the soil is made of fine, low plasticity silt (ML), and low plasticity clay (CL), according to the unified standard soil classification. The water content and plasticity limit tests (liquid limit, plastic limit, and plasticity index) demonstrated that these clays are conformable with the limits of the Iraqi standards. The results of the modified compaction test found a maximum dry density value of 1.962 g/cm3 with an optimum moisture content of 11.5%. The results of the permeability index (K) revealed low permeability according to the Das classification and, therefore, showed the suitability of the samples as raw filling materials in the construction of dams. Chemical tests (sulfate content, organic materials content, total dissolved salts, gypsum content, and pH value) showed compatibility with the requirements for the use in dams construction under the Iraqi standard (SoRB/ R5).

scholarly journals Evaluation of fine aggregates from the Budhi Gandaki-Narayani River, central Nepal for mortar and concrete

2019 ◽  
Vol 58 ◽  
pp. 69-81
Author(s):  
Ajay Babu Nayaju ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Organic Matter ◽  
Construction Materials ◽  
Compositional Analysis ◽  
Dry Density ◽  
Fine Aggregate ◽  
Hydro Power ◽  
Fine Sediments ◽  
Rock Fragments ◽  
Fine Aggregates ◽  
Lesser Himalayas

Huge amounts of construction materials are required to fulfill construction works, which are being undertaken by local and Government levels. In this regard, searching for good quality construction materials is a tough job. The Budhi Gandaki-Narayani River is rich in carrying natural fine aggregates from the Higher and the Lesser Himalayas, which are extensively exposed along its bank. Currently ongoing and future hydro power projects, will require a tremendous amount of fine aggregates. In light of this, the present study was made to evaluate fine aggregates of the Budhi Gandaki-Narayani River. The gradation curves of fine aggregates from this river varied from well graded to uniform graded. Compositional analysis shows that quartz is dominant over other minerals. Rock fragments are composed of gneiss, schist, quartzite, metasandstone, phyllite, shale, granite, etc. Deleterious materials excluding organic matter range from 0.3 % to 1.5 % and organic matter present in range from 0.57 % to 1.11 %. The trend of presence of inorganic deleterious material and organic matter is increasing towards southern segments of the river, but they remain below 2%. Mean roundness of particles ranges from 1.88 to 2.54. Bulk dry density of fine aggregate is below 2 gm/cm³. Similarly, the specific gravity ranges between 1.49 and 1.79. Fineness modulus ranges between 1.36 and 3.50 showing that, coarse, medium, fine and very fine sediments are distributed along the stretch of river. Water absorption value of fine aggregate ranges from 0.48 % to 2.87 %. When using fine aggregates from southern segments of the Budhi Gandaki-Narayani River, reduction of mica and beneficiation process will enhance and provide better result for smooth plastering, rendering and screeding.

scholarly journals Influence of Submergence on Stabilization of Loess in Shaanxi Province by Adding Fly Ash

2018 ◽  
Vol 9 (1) ◽  
pp. 68 ◽  
Author(s):  
Samnang Phoak ◽  
Ya-Sheng Luo ◽  
Sheng-Nan Li ◽  
Qian Yin
Keyword(s):  
Fly Ash ◽  
Construction Materials ◽  
Liquid Limit ◽  
Atterberg Limits ◽  
Shaanxi Province ◽  
Sustainable Construction ◽  
Dry Density ◽  
Curing Time ◽  
Maximum Dry Density ◽  
Swell Potential

In this study, the influence of fly ash (FA) content (0%, 10%, 20%, and 30%) on the alteration in the physical and mechanical parameters of loess is investigated. The influences of curing time (0, 14, and 28 days) and submergence and non-submergence conditions are analyzed as well. Analysis considers the variation in Atterberg limits (liquid limit, plastic limit, and plasticity index), compaction parameters (optimum moisture content (OMC), and maximum dry density (MDD)), unconfined compressive strength (UCS) stress, UCS strain, California bearing ratio (CBR) value, and swell potential. Results show that the application of FA-stabilized loess (FASL) is effective. Specifically, the MDD decreases and the OMC increases, the UCS stress increases and the UCS strain decreases, the CBR value improves and the swell potential declines, but Atterberg limits are insignificantly changed by the increase in the FA ratio compared with those of untreated loess. The UCS stress and CBR value are improved with the increase in curing time, whereas the UCS strain is negligible. FASL under submergence condition plays an important role in improving the effect of FA on the UCS stress and CBR value compared with that under non-submergence condition. The UCS stress and CBR value are more increased and more decreased than the UCS strain in submerged samples. Therefore, the application of FASL in flood areas is important for obtaining sustainable construction materials and ensuring environmental protection.

Compressive Strength Analysis of Ionic Soil Stabilizer Improving Soil

2015 ◽  
Vol 667 ◽  
pp. 341-346 ◽  
Author(s):  
Jue Qiang Tao ◽  
Wen Yan Lin ◽  
Xiao Hua Luo ◽  
Xin Qiu ◽  
Jin Hong Wu
Keyword(s):  
Compressive Strength ◽  
Strength Analysis ◽  
Dry Density ◽  
Optimal Dosage ◽  
Maximum Dry Density ◽  
Soil Stabilizer ◽  
Limit Test ◽  
Stabilized Soil ◽  
Compaction Degree ◽  
Curing Age

To explore the ionic liquid soil stabilizer improved soil mechanical properties, this experiment conducted liquid-plastic limit test and compaction test. On the basis of determining the optimal dosage of ionic soil stabilizer and mastering different mixture optimum moisture content and maximum dry density, the standard sample which consists of the Zhejiang red-brown clay and curing material including ionic soil stabilizer, cement and lime carried out the unconfined compressive strength test in different curing age and compaction degree. This paper analyzed the change reason of compaction and curing age about the stabilized soil. The results show that the ionic soil stabilizer has a significant effect on the compressive strength improvement of stabilized soil. Compared stabilized soil with traditional treatment soil, the compressive strength of stabilized soil has improved obviously with the increase of curing age and compaction degree. Research findings provide useful technical support and practice basis for promoting and applying ionic soil stabilizer in infrastructure construction.

Influence of Deep Foundation Pit Construction to the Surrounding Buildings - Take a Foundation Pit in Haikou as Example

2012 ◽  
Vol 268-270 ◽  
pp. 673-676
Author(s):  
Ji Nan Zou ◽  
Bei Te Cai ◽  
Hong Wei
Keyword(s):  
Large Deformation ◽  
Daily Rainfall ◽  
Shallow Foundation ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Obvious Effect ◽  
Deep Foundation Pit ◽  
Design And Construction

This paper takes example of a foundation pit in Haikou, analyzing the influence on the surrounding buildings in the course of the excavation depth, daily rainfall, foundation form of the building and other factors. The results show that the excavation depth and strong rainfall may lead large deformation of the surrounding buildings, and the deep foundation pit has obvious effect on surrounding building with shallow foundation. Therefore, those factors should be considered adequately in the design and construction of deep foundation pit

REFLECTION COEFFICIENTS AND BOTTOM LOSSES AT NORMAL INCIDENCE COMPUTED FROM PACIFIC SEDIMENT PROPERTIES

Geophysics ◽  
1970 ◽  
Vol 35 (6) ◽  
pp. 995-1004 ◽  
Author(s):  
Edwin L. Hamilton
Keyword(s):  
Normal Incidence ◽  
Silty Sand ◽  
Reflection Coefficients ◽  
Silty Clay ◽  
Sediment Properties ◽  
Compressional Waves ◽  
Sea Floor ◽  
Sediment Types ◽  
The Pacific ◽  
Clayey Silt

Rayleigh reflection coefficients and bottom losses of compressional waves at normal incidence on the water‐sediment interface are computed with values of density and velocity measured in sea‐floor sediment samples; main sediment types in three major environments of the Pacific and adjacent areas are included. Some typical average computed values of acoustic bottom loss at normal incidence in db are (1) continental shelf: sands, 8; silty sand, 10; sandy silt, 14; silty clay, 16; (2) abyssal plain: clayey silt, 17; silty clay and clay, 21; and (3) abyssal hill: silty clay and clay, 17. Comparisons with actual measurements at sea by several investigators demonstrate the validity of the approach.

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