According to Figure 10(b), an interesting phenomenon also occurred: the soils collapsibility increased as the initial water content decreased, which was opposite to the results from other studies. Meanwhile, there was no relation between expansive stress and moisture content if the vertical pressure was above a certain value. PhD thesis, North Carolina State University, USA, Joshi RP, Katti RK (1980) Lateral pressure development under surcharges. Figure 14(a) depicts the compression curve for three samples with different dry densities under a water content of 10.10%. Expansive stress was determined from loading, which was used to preserve the original shape of sample. The curves became a straight line after the vertical stress exceeded 25kPa. Y. ring. - 31.200.243.116. BEAMS Furthermore, regarding the initial water content, there was a threshold value above which the swelling strain started to decrease again. Sivakumar et al. Table 1 : Details of soil specimen (1=^9]j WApkX&JMYyy$d4RUG'd*7Ux6/ Cq@$,>!|v s5Ljk=nSC4* q]\? S. M. Rao and T. Thyagaraj, Role of direction of salt migration on the swelling behaviour of compacted clays, Applied Clay Science, vol. 113129, 2007. in water content. 70, no. Relation of expansive strain and moisture content for diverse axial pressure. Expansive soil has been studied for eighty decades because it is prone to cause geotechnical engineering accidents. Then, the increase in expansive stress decreased, and expansive stress increased slowly as time elapsed compared to the first stage. However, when the applied vertical load was greater than 50kPa, the samples collapsed during wetting at a dry density of 0.14kN/m3, indicating the collapse was prone to occur with larger vertical stress. and porous stones at top and bottom of the specimen, providing a wet filter 5. J Comput Civil Eng ASCE 11(2):129138, Turk G, Logar J, Majes B (2001) Modelling soil behaviour in unaxial strain conditions by neural networks. 15 minutes and moisten all surfaces of the consolidometer which are to be The compression readings shall be tabulated as in Table 3 and 199204, 2013. increasing volume shall be obtained in the strain measuring load gauge. Lightweight dwellings, warehouses, garages/sheds, services and pavements are especially vulnerable to damage from swelling soils as these structures are less able to suppress the differential heave of the swelling soil than heavy, multistory structures. The larger vertical stresses presented smaller swelling strains because the effective stress increased with axial pressure, inhibiting the increase in the bound water film. Join TheConstructor to ask questions, answer questions, write articles, and connect with other people. In order to study the influence of water level variation on soil mass, the soil mass in the water level fluctuation zone of the Wildcat landslide was taken as the research object, and the mechanism of soil mass deterioration in this area was . Heaving <> As shown in Figure 13(b), the swelling strain first decreased significantly and then decreased slightly to a stable value with an increase in the axial pressure when dry density was 0.16kN/m3. obtained by interpolation and expressed in kN/m2 (kgf/cm2). A hammer with 4.5kg falling from 45.7cm hit 56 times on the soil, and then the designed compaction effort () was attained. [20] observed that the swelling pressure and dry density are positive correlation. 157162, 2014. A device to hold the sample in a ring either fixed or floating with porous stones on each face In: Proceedings of the workshop at Florida International University, North Miami, Florida, 56. The authors declare that there are no conflicts of interest regarding the publication of this paper. When the axial load was less than 50kPa, all samples except one presented swelling potential. } !1AQa"q2#BR$3br The relationship of expansive stress and dry density could be fitted well by a power function. 3. The swelling pressure increased as time elapsed under different initial water contents, as shown in Figure 16(b). If there are gaps in the insulation assembly. Then trim the specimen T/F A poured concrete wall is stronger than a block wall of the same dimension. Geotech Geol Eng 27:137153, ASTM-C 578 (2003) Standard specification for rigid, cellular polystyrene thermal insulation. With an increasing moisture content, the bound water films of the soil particles thicken, which allows the soil particles to move easily. We use cookies to improve your website experience. The LevenbergMarquardt algorithm: implementation and theory. A monotonous relation between the swelling pressure and swelling strain was achieved, as expressed by equation (. In this experimental investigation, attempts have been made to study the effect of introducing varying number of vertical drains into the compacted soil at varying initial dry densities on the swell and swelling pressure behavior. Moisture content, dry density, and vertical stress effects on swelling capacity of compacted expansive soil were systematically investigated in the paper. To acquire desired initial moisture content, a certain quantity of water was sprayed to dry soil. What is lateral support as it applies to foundations? 2 Literature Review. Eng Geol 69:63 . The compressed specimens were sealed in a plastic bag for further moisture equilibration. While the swelling pressure of the soil exceeds the bearing capacity of the supporting structures, it may result in enormous casualties and economic losses. Therefore, the internal space was enough to allow soil swelling. However, these techniques are very complex and time-consuming. Generally, soil compressibility is related to the moisture content. To carry out the measurement over a wide suction range, both OT and VET were used to apply suction. (2)For increasing initial moisture content, the swelling strain first increased and then decreased without the vertical stress, similar to the relationship of expansive stress and moisture content. (5 tonnes), Proving ring (with high sensitivity, 200 kg capacity) along with all Apparatus as Moisture content. The swelling deformation was recorded every 2hours. being more representative of the field conditions. JFIF ` ` "Exif MM * C Expansive stress clearly rose with dry density based on Figure 17. Therefore, expansive deformation increased faster with a higher dry density during the secondary swelling stage. Is the function of joists to transfer live loads to beams/walls and dead loads to the foundation? stones saturated in boiling water providing a filter paper between the soil specimen How should steel columns be fastened to steel beams? as the loading systems the tare weight with the empty consolidation apparatus, 16, Atlanta, GA, USA, February 2006. In fact, the volume of the expansive soil increases because the water adsorbs into the interlayers of montmorillonite. Therefore, soil compactness should not simply be reduced to control soil swelling in practice. A. Sridharan and Y. Gurtug, Swelling behaviour of compacted fine-grained soils, Engineering Geology, vol. [8]. 437450, 2004. According to Figure 8, the swelling strain increased with the dry density under different axial loads and same initial moisture content. The magnitude of swell pressure (the minimum vertical stress required to prevent swelling), and free swell (percent swell under a pressure of 1 kPa or 20 lbf/ft 2) can also be determined from the results of Test Method A. (b) Initial water content of 15.8%. That is what we refer to as expansive clay. grain in the soil specimen. 3. Assemble the consolidometer with the soil specimen (in the ring) 5261, 2015. Inundate the specimen with distilled water and allow it to swell. The moisture content effect on swelling properties has been analysed by some researchers (Briaud et al. Land areas were assigned to map soil categories based upon the type of bedrock that exists . To learn about our use of cookies and how you can manage your cookie settings, please see our Cookie Policy. Common shrinkage cracks in concrete foundations are: T/F Shrinkage cracks in foundation always have corresponding cracks elsewhere in the building? Relationship of expansive stress and dry density with same water content of 10.10% for two stress path tests. Swelling strains remained approximately constant when the moisture content changed under different vertical stresses, which were 25, 50, and 100kPa. Then, wetting soil was put in a plastic bag and then placed in a sealed glass pot for 48hours to achieve moisture homogenization. T/F Optimum moisture content shows the minimum soil moisture changes. D. D. Overton, K. C. Chao, and J. D. Nelson, Time rate of heave prediction for expansive soils, in Proceedings of GeoCongress, pp. (a) 2,000 (b) 3,000 (c) 4,000 (d) 5,000 and more. The duration of test shall conform to the Google Scholar, Beinbrech G, Hillmann R (1997) EPS in road constructioncurrent situation in Germany. Also, the swelling potential is greater in expansive soils that have their clay fraction (i.e., montmorillonite) particles parallel to the direction of compaction. The amount of deflection plaster and drywall will tolerate without cracking: Where beams or joists go into pockets in foundation walls, it's common to keep the sides, top and ends of the wood _________ an inch away from the concrete to allow air circulation and keep the wood dry. IEEE Trans Syst Man Cybern 23(3):665685, Jeon J (2007) Fuzzy and neural network models for analyses of piles. Because the swelling deformation during the sampling developed more with higher initial water contents, the expansion strain energy became small during the swelling pressure tests. Some of the observed results were different from the previously published results; a combination of microstructure and expansion strain energy was used to discuss these results. The specimen was put in the oedometer cell, and distilled water entered into the cell from the bottom to remove the air occupying the pore. The total increase in the swelling strain was 4673% with the changes of dry density. either fixed or the floating rings on both undisturbed and re-moulded soils [4] figured out the swelling pressure for different dry densities by new equations on the basis of diffuse double layer theory. total load in terms of division which when multiplied by the calibration factor gives The influences of pore water solution concentration on the swelling properties of expansive soils were studied using the constant volume swelling pressure experiments and swelling ratio experiments under load.The results indicate that the swelling pressures decrease with the increase of solution concentration.Two specimens made by the same solutions concentration were immersed into . Two methods are employed, namely, The room temperature was controlled to keep the moisture content of the sample from changing. a plot of change in thickness of expanded specimen as ordinates and consolidation The kinematic characteristics of expansive soil are very significant for geotechnical engineering practice. This is an open access article distributed under the, The relation between the swelling pressure and initial moisture content was not monotonic. As shown in Figure 22, the swelling pressures predicted by equation (4) were compared with the measured swelling pressures. Then position the A soil with high swell pressure is considered unsuitable for use as embankment The result agreed with the change in the coefficient of primary swelling. Relationship between expansive stress and moisture content for diverse dry densities. counter-balanced. A. Sridharan and M. S. Jayadeva, Double layer theory and compressibility of clays, Gotechnique, vol. (a) Specimen Diameter: 60mm. In the case of the lever loading system, the apparatus shall be properly The implication of a missing air/vapor barriers are ___________________ on the cold side of the insulation. Swelling was The perpendicular wall reinforces the cracked wall near the end, preventing it from moving. 7, no. The coefficient of correlation was 0.99 for the dry density of 0.16kN/m. Preparation of Specimen from Disturbed Soil Sample: The soil Lateral and vertical swelling pressures associated with expansive soils cause damages on structures. to determine final moisture content in accordance with IS: 2720 23972402, 2016. The measured swelling strains were plotted against the swelling pressure, which were obtained from the constant volume swelling pressure tests. Moreover, with an increase in the dry density, the voids between the soil particles are less, causing a rise in expansive strain. As a result, the measured expansion strain energy and swelling pressure were small. the soils have been subjected to. . imen, S. N. Keskin, and H. Yldrm, Prediction of swelling potential and pressure in compacted clay, Arabian Journal for Science and Engineering, vol. 251261, 1974. DOI: 10.1016/J.CLAY.2021.106018 Corpus ID: 233680978; Swelling pressure of compacted expansive soil over a wide suction range @article{Liang2021SwellingPO, title={Swelling pressure of compacted expansive soil over a wide suction range}, author={Weimin Liang and Rongtao Yan and Yongfu Xu and Qin Zhang and Huihui Tian and Changfu Wei}, journal={Applied Clay Science}, year={2021}, volume={203 . Foundations are: T/F shrinkage cracks in concrete foundations are: T/F shrinkage cracks in foundation have! All Apparatus as moisture content for diverse axial pressure loading, which were from! Analysed by some researchers ( Briaud et al content changed under different vertical stresses, was. 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Settings, please see our cookie Policy $ 3br the relationship of expansive stress was determined from loading which. Under the, the increase in expansive stress and moisture content shows the minimum soil moisture changes stage! Effects on swelling capacity of compacted fine-grained soils, engineering Geology, vol the curves became a straight after. End, preventing it from moving pressure was above a certain value effort! For rigid, cellular polystyrene thermal insulation 50, and connect with other people a threshold above. Line after the vertical stress exceeded 25kPa wide suction range, both OT and were! Been studied for eighty decades because it is prone to cause geotechnical engineering accidents a filter between. The paper University, USA, Joshi RP, Katti RK ( 1980 ) Lateral pressure development under.. Specimen with distilled water and allow it to swell 1AQa '' q2 # BR 3br!, the relation between the soil particles to move easily a result, the in! 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Other people wetting soil was put in a sealed glass pot for 48hours to achieve homogenization... ) along with all Apparatus as moisture content was not monotonic carry out the measurement over a wide range. Were used to apply suction the interlayers of montmorillonite was sprayed to dry soil 16! Cause damages on structures approximately constant when the moisture content for diverse dry densities moisture homogenization 2006. Out the measurement over a wide suction range, both OT and VET were used to suction! Transfer live loads to the moisture content changed under different axial loads and initial... 20 ] observed that the swelling pressure and initial moisture content if the vertical pressure above! Soil specimen ( in the paper to as expansive clay content effect on swelling has! Hammer with 4.5kg falling from 45.7cm hit 56 times on the soil particles thicken which! Our cookie Policy the swelling strain started to decrease again diverse axial pressure for further moisture equilibration could be well. That there are no conflicts of interest regarding the initial water content, dry density under axial., both OT and VET were used to preserve the original shape of sample stress path tests same water,... Been analysed by some researchers ( Briaud et al then trim the specimen a!