Seismic site survey investigations in urban environments; the case of the underground metro project in Copenhagen, Denmark
Martinez, K. ; Mendoza, J. A. LU
; Colberg-Larsen, J.
and Ploug, C.
(2009)
AGU (American Geophysical Union) Spring Meeting, 2009
In Eos
90(52, Suppl.).
p.01-32
- Abstract
- Near surface geophysics applications are gaining more widespread use in geotechnical and engineering projects. The development of data acquisition, processing tools and interpretation methods have optimized survey time, reduced logistics costs and increase results reliability of seismic surveys during the last decades. However, the use of wide-scale geophysical methods under urban environments continues to face great challenges due to multiple noise sources and obstacles inherent to cities. A seismic pre-investigation was conducted to investigate the feasibility of using seismic methods to obtain information about the subsurface layer locations and media properties in Copenhagen. Such information is needed for hydrological, geotechnical... (More)
- Near surface geophysics applications are gaining more widespread use in geotechnical and engineering projects. The development of data acquisition, processing tools and interpretation methods have optimized survey time, reduced logistics costs and increase results reliability of seismic surveys during the last decades. However, the use of wide-scale geophysical methods under urban environments continues to face great challenges due to multiple noise sources and obstacles inherent to cities. A seismic pre-investigation was conducted to investigate the feasibility of using seismic methods to obtain information about the subsurface layer locations and media properties in Copenhagen. Such information is needed for hydrological, geotechnical and groundwater modeling related to the Cityringen underground metro project. The pre-investigation objectives were to validate methods in an urban environment and optimize field survey procedures, processing and interpretation methods in urban settings in the event of further seismic investigations. The geological setting at the survey site is characterized by several interlaced layers of clay, till and sand. These layers are found unevenly distributed throughout the city and present varying thickness, overlaying several different unit types of limestone at shallow depths. Specific results objectives were to map the bedrock surface, ascertain a structural geological framework and investigate bedrock media properties relevant to the construction design. The seismic test consisted of a combined seismic reflection and refraction analyses of a profile line conducted along an approximately 1400 m section in the northern part of Copenhagen, along the projected metro city line. The data acquisition was carried out using a 192 channels array, receiver groups with 5 m spacing and a Vibroseis as a source at 10 m spacing. Complementarily, six vertical seismic profiles (VSP) were performed at boreholes located along the line. The reflection data underwent standard interpretation and the refraction included wavepath Eikonal traveltime tomography. The reflection results indicate the presence of horizontal reflectors with discontinuities likely related to deep lying structural features in deeper lying chalk layers. The refraction interpretation allowed the identification of the upper limestone surface, relevant to map for tunneling design. The VSP provided additional information regarding limestone quality and provided correlation data for improved refraction interpretation. In general, the pre-investigation results demonstrated that it is possible to image the limestone surface using the seismic method. The satisfactory results lead to the implementation of a 15 km survey planned during the spring 2009. The survey will combine reflection, refraction, walkaway-VSP and electrical resistivity tomography (ERT). The authors wish to acknowledge Metroselskabet I/S for permission in presenting the preliminary results and the Cityringen Joint Venture partners Arup and Systra.
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Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/b14f103e-349a-4521-afd5-2a10eb01826a
- author
- Martinez, K.
; Mendoza, J. A.
LU
; Colberg-Larsen, J.
and Ploug, C.
- publishing date
- 2009
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Applied geophysics; 20, Engineering geology; 30, carbonate rocks;, Copenhagen Denmark;, Denmark;, depth;, elastic waves;, electrical methods;, Europe;, geophysical methods;, geophysical surveys;, ground water;, hydrogeology;, limestone;, railroads;, refraction methods;, resistivity;, rock mechanics;, Scandinavia;, sedimentary rocks;, seismic methods;, surveys;, tomography;, traveltime;, tunnels;, underground space;, urban environment;, Vibroseis;, Western Europe;
- in
- Eos
- volume
- 90
- issue
- 52, Suppl.
- pages
- 01 - 32
- publisher
- American Geophysical Union (AGU)
- conference name
- AGU (American Geophysical Union) Spring Meeting, 2009
- conference location
- Toronto, Canada
- conference dates
- 2009-05-24 - 2009-05-27
- ISSN
- 0096-3941
- language
- English
- LU publication?
- no
- additional info
- Accession Number: 2012-088021; Conference Name: 2009 joint assembly; the meeting of the Americas; Toronto, ON, Canada; Conference Date: 20090524; Language: English; Coden: EOSTAJ; Collation: Abstract NS32A-01; Publication Types: Serial; Conference; Abstract Only; Updated Code: 201222; Monograph Title: 2009 joint assembly; the meeting of the Americas; Monograph Author(s): Anonymous; Reviewed Item: Analytic
- id
- b14f103e-349a-4521-afd5-2a10eb01826a
- date added to LUP
- 2022-12-01 16:53:37
- date last changed
- 2022-12-05 11:17:48
@misc{b14f103e-349a-4521-afd5-2a10eb01826a,
abstract = {{Near surface geophysics applications are gaining more widespread use in geotechnical and engineering projects. The development of data acquisition, processing tools and interpretation methods have optimized survey time, reduced logistics costs and increase results reliability of seismic surveys during the last decades. However, the use of wide-scale geophysical methods under urban environments continues to face great challenges due to multiple noise sources and obstacles inherent to cities. A seismic pre-investigation was conducted to investigate the feasibility of using seismic methods to obtain information about the subsurface layer locations and media properties in Copenhagen. Such information is needed for hydrological, geotechnical and groundwater modeling related to the Cityringen underground metro project. The pre-investigation objectives were to validate methods in an urban environment and optimize field survey procedures, processing and interpretation methods in urban settings in the event of further seismic investigations. The geological setting at the survey site is characterized by several interlaced layers of clay, till and sand. These layers are found unevenly distributed throughout the city and present varying thickness, overlaying several different unit types of limestone at shallow depths. Specific results objectives were to map the bedrock surface, ascertain a structural geological framework and investigate bedrock media properties relevant to the construction design. The seismic test consisted of a combined seismic reflection and refraction analyses of a profile line conducted along an approximately 1400 m section in the northern part of Copenhagen, along the projected metro city line. The data acquisition was carried out using a 192 channels array, receiver groups with 5 m spacing and a Vibroseis as a source at 10 m spacing. Complementarily, six vertical seismic profiles (VSP) were performed at boreholes located along the line. The reflection data underwent standard interpretation and the refraction included wavepath Eikonal traveltime tomography. The reflection results indicate the presence of horizontal reflectors with discontinuities likely related to deep lying structural features in deeper lying chalk layers. The refraction interpretation allowed the identification of the upper limestone surface, relevant to map for tunneling design. The VSP provided additional information regarding limestone quality and provided correlation data for improved refraction interpretation. In general, the pre-investigation results demonstrated that it is possible to image the limestone surface using the seismic method. The satisfactory results lead to the implementation of a 15 km survey planned during the spring 2009. The survey will combine reflection, refraction, walkaway-VSP and electrical resistivity tomography (ERT). The authors wish to acknowledge Metroselskabet I/S for permission in presenting the preliminary results and the Cityringen Joint Venture partners Arup and Systra.<br/><br/>}},
author = {{Martinez, K. and Mendoza, J. A. and Colberg-Larsen, J. and Ploug, C.}},
issn = {{0096-3941}},
keywords = {{Applied geophysics; 20; Engineering geology; 30; carbonate rocks;; Copenhagen Denmark;; Denmark;; depth;; elastic waves;; electrical methods;; Europe;; geophysical methods;; geophysical surveys;; ground water;; hydrogeology;; limestone;; railroads;; refraction methods;; resistivity;; rock mechanics;; Scandinavia;; sedimentary rocks;; seismic methods;; surveys;; tomography;; traveltime;; tunnels;; underground space;; urban environment;; Vibroseis;; Western Europe;}},
language = {{eng}},
note = {{Conference Abstract}},
number = {{52, Suppl.}},
pages = {{01--32}},
publisher = {{American Geophysical Union (AGU)}},
series = {{Eos}},
title = {{Seismic site survey investigations in urban environments; the case of the underground metro project in Copenhagen, Denmark}},
volume = {{90}},
year = {{2009}},
}