High-resolution P- and S-wave Seismic Reflection Followed by Engineering Modeling for Geotechnical Site Characterization in Southern Illinois

A study was conducted to determine whether the structural failure of a house in a residential subdivision in southern Illinois was caused by the collapse of an old underground coal mine ( i.e. mine subsidence) or as a result of a landslide. The house was displaced approximately 5 m downhill towards an engineered lake behind it. To detect any old mines near the house, we acquired high-resolution S-wave seismic reflection profiles along the roads surrounding the subdivision and a series of high-resolution P-wave reflection profiles in the immediate vicinity of the house. The S-wave seismic reflection profiles imaged a strong shallow horizon that we interpreted as Pennsylvanian siltstone overlying the Mecca Quarry Shale and Colchester Coal, which had been previously mined in the area. Locally, this horizon showed no evidence of any recent mining activities. The high-resolution P-wave reflection profiles imaged a steeply dipping bedrock with a 20° dip at the house location. These results exclude mine subsidence from being the cause for the house failure. To investigate land sliding as a possible cause of the house failure, depths to bedrock from the seismic results together with the soil type information were used to model the soil materials with a Mohr-Coulomb stress-strain model. The engineering model demonstrated that a land slide is a more plausible cause for the house failure, which agrees with the seismic results.

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Low‐cost geophysical investigations of a paleochannel aquifer in the Eastern Goldfields, Western Australia

Geophysics ◽

10.1190/1.1484512 ◽

2002 ◽

Vol 67 (3) ◽

pp. 690-700 ◽

Cited By ~ 12

Author(s):

Josef Holzschuh

Keyword(s):

Water Table ◽

Western Australia ◽

Seismic Reflection ◽

Wave Reflection ◽

Gravity Data ◽

P Wave ◽

Gravity Modeling ◽

S Wave ◽

Sand And Gravel ◽

Gravel Aquifer

Compressional (P) wave and shear (S) wave seismic reflection techniques were used to delineate the sand and gravel aquifer within a highly saline clay‐filled paleochannel in the Eastern Goldfields of Western Australia. The seismic refraction and gravity methods were also used to investigate the paleochannel. The unsaturated loose fine‐grained sand up to 10 m in depth at the surface is a major factor in degrading subsurface imaging. The seismic processing needed to be precise, with accurate static corrections and normal moveout corrections. Deconvolution enhanced the aquifer and other paleochannel reflectors. P‐wave reflection and refraction layer depths had good correlation and showed a total of six boundaries: (1) water table, (2) change in velocity (compaction) in the paleochannel sediments, (3) sand and gravel aquifer, (4) red‐brown saprolite and green saprolite boundary, (5) weathered bedrock, and (6) unweathered bedrock. P‐wave explosive and hammer sources were found to have similar signal characteristics, and the aquifer and bedrock were both imaged using the hammer source. The deep shots below the water table have the most broadband frequency response for reflections, but stacking clear reflections was difficult. The S‐wave reflection results showed high lateral and vertical resolution of the basal saprolite clay, the sand and gravel aquifer, and very shallow clays above the aquifer. The S‐wave reflection stacking velocities were 10–20% of the P‐waves, increasing the resolution of the S‐wave section. The gravity data were modelled to fit the known drilling and P‐wave seismic reflection depths. The refraction results did not identify the top of bedrock, so refraction depths were not used for the gravity modeling in this highly weathered environment. The final gravity model mapped the bedrock topography beyond the lateral extent of the seismic and drilling data.

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High-resolution seismic-reflection profiles from Lake George, New York

Open-File Report ◽

10.3133/ofr80717 ◽

1980 ◽

Author(s):

Deborah R. Hutchinson

Keyword(s):

New York ◽

High Resolution ◽

Seismic Reflection ◽

Seismic Reflection Profiles ◽

Lake George

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Unconformities on the Scotian Shelf

Canadian Journal of Earth Sciences ◽

10.1139/e74-008 ◽

1974 ◽

Vol 11 (1) ◽

pp. 89-100 ◽

Cited By ~ 15

Author(s):

Lewis H. King ◽

Brian MacLean ◽

Gordon B. Fader

Keyword(s):

High Resolution ◽

Seismic Reflection ◽

Upper Cretaceous ◽

Scotian Shelf ◽

Early Tertiary ◽

Late Tertiary ◽

Glacial Processes ◽

Well Data ◽

Seismic Reflection Profiles ◽

Cut And Fill

Four erosional unconformities have been recognized within the Mesozoic-Cenozoic succession on the Scotian Shelf, on the basis of data from high resolution seismic reflection profiles. Older unconformities are known from well data and others may be revealed by detailed biostratigraphic studies.The oldest of the four unconformities discussed in this paper is of Early Cretaceous age and appears to mark, with discordance, the boundary between Jurassic and Cretaceous strata on the western part of the shelf. A second angular unconformity, of Late Cretaceous age, has been recognized on the central part of the shelf where the basal part of the Banquereau Formation (Tertiary and uppermost Cretaceous) oversteps the zero-edge of the Wyandot Formation (Upper Cretaceous) and lies upon truncated beds of the Dawson Canyon Formation (Upper Cretaceous). Cut-and-fill relationships characterize a third unconformity developed during Early Tertiary time. A fourth unconformity was developed in Late Tertiary – Pleistocene time by fluvial processes and later by glacial processes. Although in many areas the latest unconformity appears to be the most conspicuous one on the shelf, its configuration closely follows the geomorphic expression developed during the previous period of erosion. The regional extent of the Cretaceous unconformities is not known, and they might only occur near basin margins and on structural and basement highs.

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