02801nas|a2200241 i 450000500170000000800410001703500150005810000340007324500600010726000520016730000150021949000270023450001430026150200580040452017710046265000160223370000290224970000430227870000450232171000690236681000590243585600650249420260818145034.0121095s1979    th uu m rtt  00|  a1eng d  a.b103920751 aAtmadipradja, Tatang Sutardjo10aLaboratory model tests on displacement type sand drains  aBangkok :bAsian Institute of Technology,c1979  axi, 191 p.1 aThesis ;vno. GT-78-06  aA thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology  aThesis (M.Eng.) - Asian Institute of Technology, 1979  aIn order to study the characteristics of the foundation soil disturbed by the installation of displacement type sand drains a series of sand drain  model tests were performed in the laboratory by means of the Modified Rowe Consolidation cell apparatus Undisturbed samples were taken from depths  2.50 m to 8.0 m from the ground surface with a sample spacing of 0.75 m. Model tests with four drain columns, 1.0 cm. in diameter were performed  using cylindrical specimens of 6.0 in.in diameter and 1.5 in. thick. Also four drain columns, 1.5 cm. in diameter were installed in other specimens.  These drain columns were installed by means of a driven mini-mandrel and the  hole was filled with saturated sand. The standard consolidation tests were  performed on the undisturbed samples. The direct shear tests were also performed on consolidated specimens with sand drain columns.  It was found that the time required for the 100% primary consolidation of the specimen with sand drain columns evaluated from the compression-time relationships was longer than the time for the 100% primary consolidation of  the specimen without sand drain columns. The increase in diameter of sand columns from 1.0 cm. to 1.5 cm. increases the undrained shear strength of the speciment.  The increase in diameter of sand columns from 1.0 cm to 1.5 cm decreases the radial coefficient of consolidation. The total settlement of the specimen with sand drain columns is higher  than the total settlement of the specimen without sand drain columns. The influence of sand drains installed by driving a closed and mandrel  on the rate of consolidation, the undrained shear strength, the radial coefficient of consolidation of the soft foundation soil should be considered in the design method. 0aSand drains1 aAkagi, T., eChairperson1 aBrenner, R.P., eExamination Committee1 aHolmberg, Soren, eExamination Committee2 aUnited Nations Development Programme (UNDP), eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. GT-78-06  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B22252