WWW.THESIS.DISLIB.INFO
FREE ELECTRONIC LIBRARY - Online materials, documents
 
<< HOME
CONTACTS



Pages:   || 2 | 3 | 4 | 5 |

«GEOTECHNOLOGY FOR REBURIAL OF ARCHEOLOGICAL SITES: APPLICATIONS AND ENGINEERING by Edward Kavazanjian, Jr. Citation: Kavazanjian, E., Jr., (2004) ...»

-- [ Page 1 ] --

GEOTECHNOLOGY FOR REBURIAL OF ARCHEOLOGICAL

SITES: APPLICATIONS AND ENGINEERING

by

Edward Kavazanjian, Jr.

Citation:

Kavazanjian, E., Jr., (2004) “The use of geosynthetics for archeological sites

reburial,” Conservation and Management of Archaeological Sites, Vol. 6, No.

3 and 4, James and James (Science Publishers), Ltd., pp. 377-394

ABSTRACT

Geotechnology applications for reburial of archeological sites include infiltration and drainage control, earth reinforcement, erosion control, and surface water management. The use of geosynthetic materials provides the most common examples of application of geotechnology on reburial projects.

Geosynthetic materials applications in reburial practice include geotextiles for separation, filtration, and protection (cushioning), geomembranes and geosynthetic clay liners for infiltration control, geonets and geocomposites for subsurface drainage, and geocells for erosion control. Earth reinforcement techniques, including mechanically stabilized earth, soil nailing, and micropiles, can provide substantial benefits on reburial projects with respect to reducing lateral earth pressure against backfilled structures, supporting excavations, reinforcing walls, and supporting foundations.

Evapotranspirative capping technology for infiltration control, including capillary break systems, can facilitate design of a robust reburial system that isolates the reburied structure from moisture and temperature fluctuations.

Optimal application of these geotechnologies requires an understanding of basic engineering principles associated with their implementation.

BIOGRAPHY Edward Kavazanjian, Jr., is a registered professional geotechnical engineer and Research Professor of Civil Engineering at the University of Southern California. He is recognized for design of waste containment systems, including applications of geosynthetic materials.

INTRODUCTION

Geotechnical engineering design and construction techniques can make substantial contributions to optimal design of an archeological reburial system, from both a technical (performance) and cost perspective.

Geotechnology developed for isolation of solid and hazardous waste from the environment, for soil stabilization and erosion control, for earthwork construction associated with transportation systems and other infrastructure development projects, and for support of excavations and foundations in sensitive urban settings can be applied to many different aspects of archeological site reburial.

The use of geosynthetic materials for separation, filtration, protection (cushioning), and infiltration control has become fairly common on reburial projects. Additional applications of geosynthetic materials such as earth reinforcement and erosion control have also been appliedin reburial practice, though somewhat less frequently than other geosynthetics applications.

However, many of these applications have been ad hoc solutions rather than engineered applications, sometimes leading to ineffective or less than optimal performance, unnecessary cost, and at times even counter-productive (damaging) field performance. Design and construction techniques developed for traditional geotechnical projects (e.g., infrastructure development, waste management) can mitigate the potential for inadequate performance and reduce unnecessary expenditures when applying geosynthetic materials to reburial projects.

Modern geotechnology can make additional contributions to reburial practice beyond those provided by application of geosynthetic materials.

Earth reinforcement techniques, including soil nailing and micro-piles, developed for construction of infrastructure projects and for protection and preservation of historic structures in urban environments, can facilitate retention of backfill, reinforce deteriorating walls, and support unstable foundations. Evapotranspirative capping technology developed for the design of waste containment systems, including capillary break systems, can be used to identify the optimal configuration for a reburial scheme with respect to isolation from temperature and moisture content fluctuations in the subsurface and to isolate a buried structure from transport and deposition of minerals dissolved in subsurface moisture in the unsaturated zone. Rational and effective application of these geotechnologies requires an understanding of their advantages and limitations as well as of the engineering principles associated with their application.

GEOSYNTHETIC MATERIALS

Overview of Material Types The term geosynthetic generally refers to a man-made planar material employed for geotechnical engineering purposes. Geosynthetic materials are generally fabricated in panels, sheets, and/or rolls and are typically composed primarily of polymeric materials, though natural fibers and soils are sometimes employed when fabricating geosynthetic materials. Types of geosynthetic materials include geotextiles, geomembranes, geosynthetic clay liners, drainage cores and drainage composites, erosion control nets, geocells, and geogrids. Functions of geosynthetic materials employed in engineering practice today include separation, protection (cushioning), filtration, drainage, infiltration resistance, reinforcement, and stabilization (erosion control).





Table 1, from Bouazza (1), lists the primary functions of common geosynthetic materials.

Geotextiles include woven and non-woven fabrics and are employed for separation, protection, filtration, reinforcement, and sometimes drainage.

Geomembranes are polymeric sheets with a very high resistance to flow perpendicular to the sheet. The primary application of geomembranes is as a barrier to flow, though they have also been used for separation and protection.

A geosynthetic clay liner is composed of a thin layer of natural low permeability soil, typically bentonite (Sodium montmorillonite), either bonded to a carrier geomembrane or encased between two carrier geotextiles. The geosynthetic clay liner is also primarily used as an infiltration barrier due to its high resistance to flow perpendicular to the plane of the material.

Drainage cores are either nets composed of strands of polymeric materials or membrane-like panels and sheets with raised dimples or pedestals. When combined with a filter geotextile(s), a drainage core provides a relatively open channel for flow parallel to the plane of the core. When the drainage core and surrounding geotextile material are delivered bonded together as a single product, it is referred to as a drainage geocomposite.

Geogrids are nets or webs of high strength polymeric material used in earth reinforcement applications. Geocells are diamond-shaped cells fabricated into a sheet by linking together relatively stiff rectangular panels of polymeric material at regular intervals. Geocells provide erosion resistance by retaining soil within the cells. Geocells can also be used for earth reinforcement (e.g., to build retaining walls) or filled with concrete to form erosion resistant channel linings. Erosion control nets are open planar nets of polymeric threads and strands that hold soil in place, typically with the aid of vegetation that grows through the stands and secures the underlying soil.

Geotextiles Geotextiles are fabrics made from polymeric fibers. According to Koerner (2), over 95 percent of geotextiles are made of polypropylene or polyester, with the balance made primarily of polyethylene or nylon.

Individual fibers are sometimes twisted or spun together to form larger (thicker) strands known as yarn. The fibers or yarns are formed into geotextiles using either woven or non-woven methods.

Woven geotextiles, illustrated in Figure 1, are manufactured using traditional weaving methods and a variety of weave types. Non-woven geotextiles, illustrated in Figure 2, are manufactured by placing and orienting the fibers or yarns on a conveyor belt and bonding them by needle punching (“needle-punched”) or by heat bonding (sometimes referred to as “spunbond”). The needle-punching process consists of pushing numerous barbed needles through the fiber web, thereby mechanically interlocking the fiber into a stable configuration. In heat bonding, the fibers are heated to the point of melting and pressed together.

Geotextiles are typically provided in rolls approximately 4 m wide and from 30 to 60 m in length. Geotextiles may be seamed in the field by sewing, lystering (heat-bonding), or simple lapping. For many applications, seam strength is not important and simple lapping is sufficient. However, there are applications where the seam is required to have some strength, and sometimes seaming is useful simply to maintain the geotextile overlap until it is secured by the soil overburden. Lystering is a relatively rapid and expedient seaming process. However, lystering can weaken the geotextile, adversely affecting its performance, if too much heat is applied. Therefore, most field seams are sewn. Recently, a new generation of advanced micro-processor controlled lystering devices has been developed that significantly reduces the risk of over-heating a seam during lystering. To eliminate field seaming concerns, large geotextile panels tens of meters in dimension can be fabricated in the factory (or off-site) and delivered to the field folded in a manner that expedites deployment.

Geomembranes Geomembranes are flexible planar sheets of polymeric material.

Geomembranes may be smooth or textured, may be composed of variety of different polymers, and come in a range of thicknesses. Geomembranes are typically between 0.75 mm and 2.5 mm thick and are provided in rolls, as illustrated in Figure 3. Geomembranes are most often employed as liquid or vapour barriers due to their very low permeability. The most common types of geomembranes are high-density polyethylene (HDPE), low-density or very flexible polyethylene (VFPE), polypropylene (PP), polyvinyl chloride (PVC) and reinforced chlorosulfonated polyethylene (CSPE). However, there are a wide variety of other types of specialty geomembranes that are commercially available.

Geomembranes rolls are typically approximately 4 m wide and from 30 to 60 m in length. Roll width is generally controlled by the manufacturing process, while roll length is limited by handling considerations.

Geomembranes can also be supplied to the field in panels fabricated in the factory or offsite from geomembrane sheets the same width as geomembrane rolls. Due to its high ductility, PVC can be fabricated offsite into panels tens of meters wide. Fabricated panels are folded for handling and delivery to the site. HDPE panels, on the other hand, are rarely more than one roll width due to the limited ductility of HDPE.

Field seaming techniques for geomembrane rolls and panels include fusion welding, extrusion welding, and gluing. In fusion welding, two pieces of HDPE are joined together by heating them under pressure. The most common fusion weld is a “double track weld” that creates two parallel lines along with the geomembrane is fused together. This type of weld allows for non-destructive air pressure testing of the seam integrity along its entire length. Extrusion welding involves placing a molten bead of material (extrudate) along the seam. The extrudate bonds to both pieces of material as it cools, joining them together. In a glued seam, the adjacent pieces are joined together by an adhesive. Seams can also simply be lapped without physically joining the pieces.

Fusion welding is the preferred method of geomembrane seaming for environmental applications because it provides a high strength, redundant seam that facilitates non-destructive integrity testing. In areas where fusion testing is not possible (e.g., at corners and connections), extrusion welding is generally employed. Gluing is not generally used with HDPE or PP geomembranes due to their low ductility (which makes it difficult to glue pieces that are not perfectly flat), concerns over seam longevity, and, on environmental projects, concern over the volatile organic compounds present in most glue. Lapping is only used in non-critical situations, as it does not create a good barrier to moisture or vapor migration unless both pieces are perfectly flat and a relatively high normal stress is applied at the connection.

Geosynthetic Clay Liners A geosynthetic clay liner (GCL) is a sheet of dry, granulated sodium montmorillonite clay, commonly referred to as bentonite, which is either glued to a carrier geomembrane or secured between two carrier geomembranes by needle punching or stitching. Figure 4 illustrates these two types of GCL. Figure 5 shows a needle punch-reinforced fabric encased GCL.

The bentonite layer in a GCL is typically 6 mm thick. GCLs are the primary alternative to geomembranes for creating a hydraulic barrier with geosynthetic materials: due to the low permeability of bentonite: a 6-mm thick GCL is roughly hydraulically equivalent to 1 to 2 meters of the type of clay soil typically used in landfill liners and covers. GCLs are typically supplied in rolls of dimensions similar to geomembranes. However, rolls more than 30 m in length are difficult to handle due to their weight (a 30 m long roll of GCL weight approximately 0.75 tonnes).

GCLs are seamed by simply lapping adjacent sheets, with powdered bentonite applied to the seam for some of the needle punched products.

Laboratory testing indicates that lapping in this manner produces a seam highly resistant to fluid flow as long as sufficient normal stress) typically the equivalent of 0.5 m of soil) is placed on the seam.



Pages:   || 2 | 3 | 4 | 5 |


Similar works:

«Michael Ivankovich Auction #79 KD Smith Auction Gallery, Allentown, PA Lot # Title Description Start Low High 1 Wallace Nutting A Bit of Circa 1905-10 Wallace Nutting hand-colored photo. Rare and very early Colonial Interior scene. New England. Original $50 $100 $250 Innocent Gossip mat, title, and pencil signature. Est 17w x 14h original frame with no backing paper. 4.0 Grading with good color and in clean and un-blemished condition. From the Richard and Dorothy Manville Collection. 2 Wallace...»

«A Cursory Overview and Comparison of Four Architecture Description Languages February 18, 1993 Steve Vestal Honeywell Systems & Research Center (612) 951-7049 vestal@src.honeywell.com 1 Introduction An Architecture Description Language (ADL) for software applications focuses on the high-level structure of the overall application rather than the implementation details of any speci c source module. ADLs are intended to play an important role in megaprogramming, which is the development of...»

«THE HUNT FOR COLONEL FAWCETT “For every Colonel Fawcett known to the world, there are a hundred such who have disappeared and remain entirely unheard of.” (The Rivers Ran East, Leonard Clark, 1953) The Making of an Adventurer Percy Harrison Fawcett (1867-?) was born in Torquay, Devon in 1867. His Indianborn father Edward was something of a rake, a friend of the Prince of Wales, and a Fellow of the Royal Geographical Society, from whom young Percy undoubtedly got his penchant for adventure...»

«Sensual Preciousness: the Earthfolk vision and practice of living peacefully and comfortably at home on the Living Earth Earthfolk Papers, Volumes 1 and 2 by Francis X. Kroncke ©2010 This text is linked to http://www.earthfolk.net Francis X. Kroncke, fkroncke@earthfolk.net INTRODUCTION TO VOLUMES 1 AND 2 Sensual Preciousness, Volumes 1 and 2, introduces the Earthfolk and our vision and practices of living peacefully and comfortably at home on the Living Earth. This is a fundamentally distinct...»

«Symmetry 2015, 7, 1-14; doi:10.3390/sym7010001 OPEN ACCESS symmetry ISSN 2073-8994 www.mdpi.com/journal/symmetry Article A Study on Electronic-Money Technology Using Near Field Communication Min Soo Jung Department of Computer Engineering, Kyungnam University, 7 Kyungnamdaehak-ro, Masanhappo-gu, Changwon-si 631-701, Korea; E-Mail: msjung@kyungnam.ac.kr; Tel.: +82-55-249-2217; Fax: +82-55-248-2554 Academic Editors: Young-Sik Jeong, Laurence T. Yang, Stefanos Gritzalis Received: 11 August 2014 /...»

«PUBLISHED UNITED STATES COURT OF APPEALS FOR THE FOURTH CIRCUIT No. 15-6568 LEWIS DUCKETT, Plaintiff Appellant, v. MARCIA FULLER, SCDC Dietician in their individual or personal capacities; MRS. BALL, First Name Unknown Kershaw Cafeteria Supervisor in their individual or personal capacities; MICHAEL L. FAIR, Legislative Audit Counsel in their individual or personal capacities; SC DISTRICT 6, Greenville County State Senate in their individual or personal capacities; BOYD H. PARR, Director of...»

«We ought to obey God rather than men God’s grace in the life of a priest Nino Tirelli Dear brothers and sisters, dear friends, in gratitude and praise to the Triune God and in the joy of our salvation freely granted through the Blood of the Lamb, I rejoice in this opportunity to present my testimony to you, as I remember His promise, “Whosoever therefore shall confess me before men, him will I confess also before my Father which is in heaven.” (Matthew 10:32) God's Word declares, “the...»

«Predestination Biblical and Theological Paths MATTHEW LEVERING Contents Acknowledgements ix Introduction 1 1. The Biblical Roots of the Doctrine of Predestination 13 2. The Patristic Period: Outlining the Problem 36 3. The Medieval Period: Seeking a Balance 68 4. The Reformation and Early Modern Period: Causal Chains 98 5. The Twentieth Century: God’s Absolute Innocence 135 6. Two Affirmations 177 Works Cited 202 Index 225 The Biblical Roots of the Doctrine of Predestination The interest in...»

«Sensors 2014, 14, 8217-8234; doi:10.3390/s140508217 OPEN ACCESS sensors ISSN 1424-8220 www.mdpi.com/journal/sensors Article Smartphone Sensors for Stone Lithography Authentication Giuseppe Schirripa Spagnolo *, Lorenzo Cozzella and Donato Papalillo Dipartimento di Matematica e Fisica, Università degli Studi ―Roma Tre‖, Via della Vasca Navale 84, I-00146 Roma, Italy; E-Mails: lorenzo.cozzella@uniroma3.it (L.C.); donato.papalillo@uniroma3.it (D.P.) * Author to whom correspondence should be...»

«Recovering Experimental Religion Sherman Isbell E xperimental religion, which once was a vital part of the Reformed tradition of preaching and spirituality, has in a large measure been lost sight of in our day. Even use of the term experimental in connection with religion is no longer customary, it being more commonly associated with the natural sciences, where a method of probing and investigation leads to an understanding of reality. The older Reformed writers used the word to indicate that...»

«CENTRAL MICHIGAN UNIVERSITY BOARD OF TRUSTEES February 18, 2016 Central Michigan University Board of Trustees Mt. Pleasant, Michigan February 18, 2015 Chair Sarah R. Opperman called the meeting of the Board of Trustees to order at 8:30 a.m. in the President’s Conference Room in the University Center. Members present: Mr. John D. Hurd; Mr. William R. Kanine; Ms. Tricia A. Keith, vice chair; Ms. Patricia E. Mooradian; Ms. Sarah R. Opperman, chair; Dr. George E. Ross, president; Mr. Richard K....»

«Cognitive Science 30 (2006) 945–982 Copyright © 2006 Cognitive Science Society, Inc. All rights reserved.Learning Phonology With Substantive Bias: An Experimental and Computational Study of Velar Palatalization Colin Wilson Department of Linguistics, UCLA Abstract There is an active debate within the field of phonology concerning the cognitive status of substantive phonetic factors such as ease of articulation and perceptual distinctiveness. A new framework is proposed in which substance...»





 
<<  HOME   |    CONTACTS
2017 www.thesis.dislib.info - Online materials, documents

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.