Explosive Compaction of Sand Foundation: In Situ Trails

2011 ◽  
Vol 147 ◽  
pp. 176-182
Author(s):  
Jun Tong Qu ◽  
Zhi Hong Ran ◽  
Sheng Miao
Keyword(s):  
Efficient Method ◽  
Soil Improvement ◽  
Cohesive Soils ◽  
Explosive Compaction ◽  
Widespread Acceptance ◽  
Soil Densification

It is necessary to find a more economical soil improvement technique to densification the reclamation by bumping filling foundation. As a soil improvement technique, blasting-densification of sand is a viable and efficient method, which offers several advantages compared to other soil densification methods. Although Explosive Compaction (EC) has been used effectively for compaction loose, non-cohesive soils for more than 70 years, it has not attained widespread acceptance in China. In-situ trials of Explosive Compaction were carried out to determining appropriate and feasible of Explosive Compaction for improvement sand foundation.

A facile one pot route for the synthesis of imide tethered peptidomimetics

2016 ◽  
Vol 14 (2) ◽  
pp. 556-563 ◽  
Author(s):  
Veladi Panduranga ◽  
Girish Prabhu ◽  
Roopesh Kumar ◽  
Basavaprabhu Basavaprabhu ◽  
Vommina V. Sureshbabu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Efficient Method ◽  
One Pot ◽  
Protected Amino Acid

A simple and efficient method for the synthesis of N,N’-orthogonally protected imide tethered peptidomimetics is presented. The imide peptidomimetics were synthesized by coupling the in situ generated selenocarboxylate of Nα-protected amino acids with Nα-protected amino acid azides in good yields.

scholarly journals ANALISIS PENGGUNAAN PREFABRICATED VERTICAL DRAINS (PVD) PADA TANAH LEMPUNG LUNAK YANG TERDAPAT LAPISAN LENSA

2020 ◽  
Vol 3 (1) ◽  
pp. 119
Author(s):  
Andreyan Prasetio ◽  
Aniek Prihatiningsih
Keyword(s):  
Soft Soil ◽  
Soil Improvement ◽  
Cohesive Soils ◽  
Consolidation Process ◽  
Prefabricated Vertical Drains ◽  
Soil Layers ◽  
Vertical Drains ◽  
Vertical Drain ◽  
Installation Depth ◽  
Consolidation Time

Problem that often occurs in soft cohesive soils is settlement caused by consolidation process. If  construction activities doing when the soils has not been consolidated, settlement can occur. To accelerate  the consolidation process, soil improvement are usually do, one method of soil improvement to accelarate the consolidation process is vertical drain using prefabricated vertical drains (PVD). The soft soil layers in the field are not always continuous, sometimes found soft soil layers that have a lens layer. In this study, will discuss about the settlement and consolidation time of soft  soil layers that have a lens layer which has been improved by PVD with 1 meter distance. Infrastructure that stand on a location that is installed by PVD is taxiway and loading by Airbus A380 aircraft of 18,22ton/m2. Analysis using the 1 dimensional consolidation theory of Terzaghi. For PVD installation to a depth of 50 meters, preloading settlement of 234,80 cm with a consolidation time of  2260 days for the square pattern PVD and 1918 days for triangle pattern PVD. Post loading settlement for PVD installation depth of 50 meters by 2,50 cm. AbstrakMasalah yang sering terjadi pada tanah kohesif dan lunak adalah penurunan yang disebabkan proses konsolidasi. Penurunan dapat menyebabkan keretakan pada struktur konstruksi yang berada di atasnya. Jika suatu kegiatan konstruksi dilakukan saat tanah belum terkonsolidasi, maka konstruksi tersebut dapat mengalami penurunan.. Untuk mempercepat proses konsolidasi biasanya dilakukan perbaikan tanah, salah satu metode perbaikan tanah untuk mempercepat proses konsolidasi yaitu vertical drain dengan menggunakan prefabricated vertical drains (PVD). Lapisan tanah lunak yang terdapat di lapangan tidak selalu kontinu, terkadang ditemukan lapisan tanah lunak yang terdapat lapisan lensa. Pada penelitian ini, penulis akan membahas mengenai waktu konsolidasi yang dibutuhkan oleh lapisan tanah kohesif dan lunak yang terdapat lapisan lensa yang telah diperbaiki dengan menggunakan PVD berjarak 1 meter. Infrastruktur yang berdiri di atas lokasi yang dipasang PVD berupa taxiway dengan beban berupa pesawat Airbus A380 sebesar 18,22 ton/m2. Analisis dilakukan menggunakan teori konsolidasi 1 dimensi Terzaghi. Untuk pemasangan PVD hingga kedalaman 50 meter diperoleh penurunan pra pembebanan sebesar 234,80 cm dengan waktu konsolidasi selama 2260 hari untuk pemasangan PVD pola persegi dan selama 1918 hari untuk pola segitiga . Penurunan pasca pembebanan untuk pemasangan PVD hingga kedalaman 50 meter sebesar 2,5 cm.

Synthesis of Symmetrical Dipurine-Nucleoside Diphosphates from the Corresponding Nucleoside Phosphoropiperidates

2014 ◽  
Vol 1023 ◽  
pp. 55-58
Author(s):  
Xiao Chuan Li ◽  
Shan Shan Gong ◽  
Qi Sun
Keyword(s):  
Efficient Method ◽  
Good Yield ◽  
Purine Bases ◽  
Hydrolysis Of

A general and efficient method for the preparation of symmetrical dinucleoside diphosphates with purine bases has been developed. Ap2A and Gp2G were synthesized from the in situ hydrolysis of corresponding nucleoside 5′-phosphoropiperidates with 4,5-dicyanoimidazole as the activator. This method features easily accessible starting materials, simple procedures, and good yield.

The Acceleration of the Rearrangement of α-Hydroxy Aldimines by Lewis or Brønsted Acids

Synlett ◽  
2018 ◽  
Vol 29 (15) ◽  
pp. 2015-2018 ◽  
Author(s):  
William Wulff ◽  
Xin Zhang ◽  
Yijing Dai
Keyword(s):  
Silica Gel ◽  
Efficient Method ◽  
Bronsted Acids ◽  
High Yields

An efficient method was developed for the synthesis of α-amino ketones from α-hydroxy imines. The reaction occurs through an α-iminol rearrangement involving the migration of a substituent of the carbinol carbon to the imine carbon. The optimal catalysts were found to be silica gel or montmorillonite K 10, which effected migration of a variety of aryl and alkyl substituents in high yields. The rearrangement can also be carried out on imines generated in situ from aldehydes and amines in essentially the same yields as those from the preformed imines.

A mild and efficient method for the reduction of oximes to imines for futher in situ reactions

1984 ◽  
pp. 337 ◽  
Author(s):  
Derek H. R. Barton ◽  
William B. Motherwell ◽  
Ethan S. Simon ◽  
Samir Z. Zard
Keyword(s):  
Efficient Method ◽  
In Situ Reactions

A simple and efficient method for the synthesis of gem-diacetates from aldehydes and ketones catalysed by gallium triiodide

2005 ◽  
Vol 2005 (10) ◽  
pp. 659-660 ◽  
Author(s):  
Peipei Sun ◽  
Zhixin Hu
Keyword(s):  
Acetic Anhydride ◽  
Ambient Temperature ◽  
Efficient Method ◽  
Carbonyl Compounds ◽  
Aldehydes And Ketones

Aldehydes or ketones reacted with acetic anhydride in dichloromethane at ambient temperature to produce gem-diacetates in good to excellent yields in the presence of gallium triiodide, which was generated in situ from gallium and iodine. This catalyst was also useful for the deprotection of carbonyl compounds in the presence of water.

Laboratory Testing: Assessing BS 5930

1986 ◽  
Vol 2 (1) ◽  
pp. 43-52 ◽  
Author(s):  
D. W. Hight
Keyword(s):  
Effective Stress ◽  
Site Investigation ◽  
Triaxial Tests ◽  
Cohesive Soils ◽  
Deformation Parameters ◽  
Strength And Deformation ◽  
Soil Behaviour ◽  
Measured Strength ◽  
Linear Nature

AbstractEstablished patterns of soil behaviour are used to illustrate: the divergence between parameters from laboratory and in situ tests; the changes in effective stress caused by sampling; and the influence of initial effective stress, p′0 on the measured strength and deformation parameters for cohesive soils.Current practice in onshore site investigation continues to make use of the unconsolidated undrained triaxial test in which p′0 is not controlled. Variations in p′0 after sampling and subsequent handling are shown to contribute to the scatter in undrained compression strength data.A plea is made for BS 5930 to encourage the measurement of effective stress in all undrained triaxial tests; to recognise the non-linear nature of soils; and to urge integration of laboratory and in situ tests.

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