Bs 1377 Part 3 1990 Pdf Reader
Gypseous soils are distributed in vast areas and various regions of Iraq and other countries. Many foundation failure problems that occur in these soils are associated with percolation of water and dissolution of gypsum.
Lookup Mercury Marine outboard motor parts by engine model and buy discount parts and accessories from our large online inventory. Bs 5839 part 6 2013 pdf - books reader Bs 5839 Part 6 2013 downloads at Booksreadr.org. Car service manual free love systems routines manual vol 1 pdf manual. Twilight part 1, first aid nbde part 1 free. Cma part 1 2011 bs5839 part 1 2008 pdf bs5839 part 1 pdf. Besides challenging me, I mean; with a ponytail.
Many attempts were made by several researchers to treat and improve the properties of gypseous soils to decrease the dissolution of gypsum and collapse potential of these soils. The purpose of the present work is to investigate the effect of dynamic compaction process on the behaviour of gypseous soils. Extensive laboratory tests are carried out to study the geotechnical properties and the behaviour of three gypseous soils of different gypsum contents; 60.5, 41.1 and 27%.
The tests included compaction characteristics, compressibility, and collapsibility tests for samples tested before and after treatment by dynamic compaction process under different number of blows, falling weights and heights of falling of the weights. Three weights are used to compact the samples, namely; 2, 3 and 5 kg. The number of blows is varied between 20 and 40, while three heights of drop are tried (35, 50 and 65) cm. The results showed that the best improvement in compressibility is achieved when the sample is compacted by 20 blows; above this number a negligible decrease in the compression index CC is obtained.
As the gypsum content increases, the dynamic compaction has greater effect on improvement of compressibility of the soil, while as the height of drop increases, the compression index CC decreases. Fattah012Hawraa H.
Al-Musawi012Firas A. Salman Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur,Malaysia1H. Al-Musawi Civil Engineering Department, College of Engineering, University of Kufa, Kufa,Iraq2M. Fattah (&) Building and Construction Engineering Department, University of Technology, Baghdad,IraqGypseous soils are distributed in vast areas and various regions of Iraq and other countries. Many foundation failure problems that occur in these soils are associated with percolation of water and dissolution of gypsum. Many attempts were made by several researchers to treat and improve the properties of gypseous soils to decrease the dissolution of gypsum and collapse potential of these soils.
The purpose of the present work is to investigate the effect of dynamic compaction process on the behaviour of gypseous soils. Extensive laboratory tests are carried out to study the geotechnical properties and the behaviour of three gypseous soils of different gypsum contents; 60.5, 41.1 and 27%. The tests included compaction characteristics, compressibility, and collapsibility tests for samples tested before and after treatment by dynamic compaction process under different number of blows, falling weights and heights of falling of the weights. Three weights are used to compact the samples, namely; 2, 3 and 5 kg. The number of blows is varied between 20 and 40, while three heights of drop are tried (35, 50 and 65) cm. The results showed that the best improvement in compressibility is achieved when the sample is compacted by 20 blows; above this number a negligible decrease in the compression index CC is obtained.
As the gypsum content increases, the dynamic compaction has greater effect on improvement of compressibility of the soil, while as the height of drop increases, the compression index CC decreases.1 Introductionand today engineering properties of these soils in someareas are unknown. The basin of Iraq covers more thanabout 30% of Iraqi area (Nashat 1994).Gypseous soils usually stiff when they are dry, butthese soils may be affected greatly when subjected tochanges in water content due to water tablefluctuation, or due to water infiltration which may dissolvegypsum causing, pores, cracks and producing cavitiesthat lead to increase the permeability in gypseoussoils. Therefore, the safety and good performance ofthe foundations of structures and earth structures, suchas embankments and dams, will be governed by thechanges in the properties of these soils.Rollins et al. (1998) evaluated the influence ofmoisture content on dynamic compaction efficiency atsix field test cells, each with a progressively higheraverage moisture content.
The soil profile consisted ofcollapsible sandy silt, and average test cell moisturecontents ranged from 6 to 20%. At each cell,compaction was performed with a 4.54 ton weight dropped froma height of 24.3 m. Compaction efficiency wasevaluated using (1) crater depth measurements, (2) conepenetration tests before and after compaction, and (3)undisturbed samples before and after compaction.
It wasfound that crater depth increased by a factor of 4 asmoisture content increased. The degree of improvementincreased up to a moisture content of about 17% andthen decreased. The optimum moisture content and themaximum dry unit weight are similar to those predictedby laboratory Proctor testing using energy levelscomparable to those employed in the field. Maximumdry unit weight decreased with depth, while optimummoisture content increased before the compactiveenergy decreased with depth below the impact point.Rollins and Mark (2005) described the dynamiccompaction carried out in Wyoming. The deep dynamiccompaction (DDC) work typically involved a 20 tonweight, 4 ft (1.22 m) in diameter, with a drop height of100 ft (30.48 m). Generally, primary drop points werespaced at 10 and 12 ft (3.05 and 3.66 m) on centerstransverse and parallel to the direction of traffic,respectively. Secondary drops were spaced at the centerof four primary drop points.
Five drops were typicallymade at each primary drop point and 2 at eachsecondary point. The number of drops per point wastypically limited to 5 or 6 for the primary points and 23for the secondary points.
The applied energy pervolume increased from about 60% of the standardProctor test energy in the 19891990 work to about95% for the second set of tests. These relatively highenergy levels are common for treating collapsible soils.Inspectors monitored the number of drops and the craterdepth for each drop point. The average crater depthswere typically between 5 and 7 ft (1.52 and 2.13 m)deep after treatment and the crater diameter typicallyincreased to about 10 ft (3.05 m) at the ground surface.Dynamic cone penetration tests were performed atseveral locations along each roadway section beforeand after treatment.
Substantial increases in conepenetration resistance occurred when soil typesconsisted of silty sands (SM) or low-plasticity silts (ML orCL-ML) and the natural water content was relativelylow. In these cases, the average penetration resistanceincreased from an average of 57 blows/ft to an averageof 2530 blows/ft. However, in cases where the soilprofile contained layers of plastic clay (CH) with highernatural water contents, little improvement inpenetration resistance was observed.
Bs 1377 Part 2 1990
Under these conditions,the clay soil appeared to absorb a significant percentageof the impact energy rather than transmitting it to thedeeper layers.Rollins and Kim (2010) presented case historiesprovided for 15 projects at 10 locations in the UnitedStates where collapsible soils were treated withdynamic compaction (DC). For each site, the soilproperties, compaction procedures, and subsequentimprovement were summarized. Althoughcohesionless and low-plasticity collapsible soils weresuccessfully compacted, clay layers in the profile appearedto absorb energy and severely reduced compactioneffectiveness.
Bs 1377 Part 9
Correlations were presented forestimating the maximum depth of improvement, the degree ofimprovement versus depth, the depth of craters, and thelevel of vibration based on measurements made at thevarious sites. The compactive energy per volume wastypically higher than for non-collapsible soils becausecollapsible soils are usually loose but relatively stiff.The maximum depth of improvement was similar tothat for non-collapsible soils; however, significantscatter was observed about the best-fit line.Improvement was non-uniform with nearly 80% of the totalimprovement occurring within the top 60% of theimprovement zone.
Related Posts
- Embarcadero Rad Studio Xe 2 Serial
- Arirang 4500 Deluxe Manual High School
- Redgate Sql Prompt Keygen Download
- Corel Photo Paint Registration Crack Fruity
- Principles Of Marketing By Philip Kotler 13th Edition Ppt Background
- Warriors Orochi 2 Psp Torrent Download
- Download Latest Os For Blackberry Bold 9790
- Hauppauge Wintv Hvr 900 Drivers Download
- Gembird Usb To Serial Driver Download
- Free Download Hotstar Go Solo Apk