Auger Borings Research Articles

Characterization and classification of rice-growing soils on Imo clay shale residua in Eastern Nigeria and current suitability for rice production: II. Anaku and Igbariam communities.

The soils on Imo Clay Shale residua were sampled at Anaku and Igbariam in Anambra state, Nigeria to characterize, classify and evaluate their current suitability for rice production following standard scientific procedures. After several auger borings, modal profiles were sited, dug, described, and sampled. The soils generally belong to loamy textural classes or finer, especially in the subsoil layers. The morphological and physical properties of soils showed that the soils were poorly drained, favouring high water retention due to low hydraulic conductivity and slow permeability. All these conditions favour good rice performance. Though the soils contained high levels of exchangeable bases, exchangeable acidity was equally high leading to low base saturation (< 35%). Thus, the soils were classified as Typic Kanhaplaquults (Soil Taxonomy) and correlated to Gleyic Cambisols (World Reference Base for Soil Resources). Due to fertility inadequacies, the current suit- ability unit of the soils for rice production is suitability class 2 with fertility constraints (S2f). This implies that for sustainable rice production supplementary nutrients especially P2O5 from triple superphosphate or rock phosphate need to be applied. Based on the soil chemical results the following recommendations were made for optimum rice production: 100.00-120.00 kg ha‒1 urea, 60.00 kg ha‒1 P2O5 from triple superphosphate and 15.00 kg ha‒1 K2O (muriate of potash).

Influence of farming systems practices on physicochemical properties of soils in wet and dry season in University of Port Harcourt, Nigeria

We evaluated the impact of cultural practices on arable cropped farmlands of more than 5 years of slash, burn, continuous mixed cropping of crops on physicochemical properties of soils in University of Port Harcourt, Nigeria. 22 cultivated arable farmlands and 3 fallow control sampled in June 2020 as wet and January 2021 as dry season 0-15cm depth from 7 auger borings taken randomly from each of the 22 cultivated and 3 fallows farmlands. Samples air dried in laboratory, prepared for analyses, sent to Fatlab in Ibadan Nigeria. Parameters evaluated for physical properties: sand, clay and silt and for chemical properties; pH, Ca, Mg, K, Na and the trace metals; Mn, Fe, Cu, Zn; available P, OC, ECEC, Acidity and Al. The results revealed sandy loam, differences between the mean values for wet season were slightly higher from the dry season, for example pH, Ca, Mg, K, Na, ECEC, Cu, Silt and Clay. The mean value of P in wet season was 5 times higher than dry season. N in wet and dry season mean value were 0.16% respectively; OC was higher in dry season indicating soil healing process before next season cropping. Slight trace of Al in dry season. However, it was significant (p<0.05) between dry and control season, comparison between wet and dry season revealed P, OC, Mg, K, Na, N, Sand and Clay significant (p<0.05). It was observed slash, burn, continuous tillage, mixed cropping of crops and times of the year influence soil physicochemical properties in arable farmland in humid high rain forest.

An investigation on perpetual asphalt pavements in Minnesota

Asphalt Pavement Alliance (APA) created the Perpetual Pavement Award program in 2001. This program requires that the roadway has at least 35 years of service at the time of award and had experienced no structural failures. In addition, the program limits candidate roadways to those that have not received more than 100 mm of new asphalt nor have been resurfaced at a frequency exceeding 13 years. Minnesota Department of Transportation (MnDOT) currently owns the record for the most award winners and has received an award every year from 2002 through 2017. This study reviews all the award-winning roadways in Minnesota to determine common material, design factors and considerations which may have contributed to the roadways extended life, often exceeding 50 years, despite the harsh Minnesota climate. For these projects, all the available information and any pertinent supporting information were reviewed. Findings from this review showed that a combination of many different factors including large-scale subgrade correction, utilizing non-frost susceptible base and subbase materials, bituminous treatment of the granular layers, utilization of prime coat, and staged construction may have contributed to the outstanding performance of these award-winning roadways. In addition, a more in-depth analysis was performed on the four project locations within the Minnesota Metro District. To further investigate and characterize these sites, coring and hand auger borings were performed in cracked and un-cracked areas along with Dynamic Cone Penetrometer (DCP) test which the results indicated that the in-situ materials were strong in all the projects. The cores were then used to measure thicknesses, densities, asphalt contents, extracted gradations, and also to perform resilient modulus testing at low and intermediate temperatures. Resilient Modulus testing showed that the asphalt mixtures from different projects perform differently at intermediate temperatures, but this difference is much less pronounced at low temperatures. This could be one reason for the similar long-life behavior of these pavements, as they have been subjected to the low temperature condition in a substantial portion of their service life in the state of Minnesota.

Identification of environmental factors controlling wine quality: A case study in Saint-Emilion Grand Cru appellation, France

Soil is a key component of the terroir concept for wine production. Indeed, the soil provides water and nutrients to the vine plants depending on its properties and environmental conditions. A part of the complexity in the production of high-quality wines is the adaptation of the winegrowing practices to soil conditions variability in space and time. Then, a deep understanding of the environmental conditions that modulate soil-plant system functioning and control the production of quality wine is crucial for future global change adaptation. This study aimed to identify environmental factors controlling red wine quality by merging both winemaker and scientist knowledge. This work was performed on a vineyard in Saint-Emilion Grand Cru appellation, France. First, we conducted field investigations for micro-terroir scale soil mapping in 2017, based on pedological prospections (pits and auger borings) and both water table levels and main meteorological parameters monitoring (from November 2017 to November 2018). Additionally, we collected for each vineyard plot the corresponding wine quality rank established each year since 2012 and based on wine tasting sessions supervised by the winemakers. Subsequently we investigated both nutrients and water availability for the vine. This was achieved through correlative analysis using soil description, roots observation and water table level, stratified according to both soil functional units and wine quality ranks maps. Results show that the water table dynamic and the soil texture have a major impact on the root pattern of vines. Our study suggests that explanatory factors for wine quality are interactions between soil-water and roots during vine crop season. Here, best soils for fine wines could be observed for both non-severe water deficit and no-limited nutrient conditions.

A mid to late Holocene history of floodplain and terrace reworking along the middle Delaware River valley, USA

This study tests and refines the traditional floodplain development model for the partly confined middle Delaware River valley, which has shown that the main channel was relatively stable and flanked by a 6000–8000year old, vertically accreting alluvial terrace. The Holocene alluvial processes and history presented here in 6 fluvial phases were reconstructed using morphostratigraphy, 36 profile descriptions, 332 grain size analyses, and 82 14C ages from soil trenches, auger borings, and archaeological excavations. Fluvial phases I–III largely validate previous reconstructions showing a late Pleistocene (I: >10.7ka) braided stream transition into an early Holocene wandering stream with prolonged floodplain stability (II: 10.7–8ka), followed by early–middle Holocene erosion and then deposition (III: 8–5ka). The early and middle Holocene changes in alluvial stratigraphy and sedimentology broadly correlate with climatically derived Holocene subdivisions, suggesting climate change partly controls alluvial response along the middle Delaware River valley. This study documents for the first time a middle Holocene episode of channel incision occurring sometime between 6.0 and 5.0ka. Although the results reconfirm that the majority of alluvial landforms are composed of vertical accretion deposits, we present here new evidence of oblique, abandoned channel, and lateral accretion deposits inset to similar landforms with different formation histories (i.e., polycyclic terrace development), depicting a river valley that has experienced floodplain and terrace reworking. The majority of floodplain and terrace reworking occurs during the late–middle and late Holocene phases IV–VI (5.5–0ka), following the middle Holocene incision event. These phases demonstrate floodplain reworking processes in the form of channel abandonment, stripping, flood channeling, and convex bank erosion. The subsequent space filled rapidly with evidence of multistory soil formation, and eventually resulted in alluvial fill terraces with heights comparable to older surfaces. The most recent fluvial phase, VI (1.0–0ka), shows markedly faster sedimentation rates and coarser flood deposits associated with peak prehistoric population and the onset of Euroamerican settlement. The results presented here contribute newly documented evidence of erosion and depict a river valley that has undergone middle Holocene incision and floodplain and terrace reworking since the late–middle Holocene. Stream modelers, fluvial geomorphologists and geoarchaeologists working in the NE USA should consider floodplain reworking processes when examining alluvial history and predicting changes in stream dynamics.

Documenting Liquefaction and Lateral Spreading Triggered by the 12 January 2010 Haiti Earthquake

The 12 January 2010 Haiti earthquake (Mw 7.0) caused extensive damage to the Port-au-Prince region, including severe liquefaction failures along the Gulf of Gonâve coastline, along rivers north of Port-au-Prince draining into the Gulf, and a liquefaction-induced structural/bearing capacity failure of a three-story concrete hotel along the southern coast of the Gulf. During two reconnaissance missions, the authors documented ground conditions and performance at eight sites that liquefied and two sites that did not liquefy. Geotechnical characterization included surface mapping, dynamic cone penetration tests, hand auger borings, and laboratory index tests. The authors estimated median peak ground accelerations (PGAs) of approximately 0.17g to 0.48g at these sites using the Next Generation Attenuation (NGA) relations summarized by Power et. al. (2008) . These case histories are documented here so that they can be used to augment databases of level-ground/near level-ground liquefaction, lateral spreading, liquefaction flow failure, and liquefaction-induced bearing capacity failure.

Spatial Distribution of Carbon in the Subsurface of Riparian Zones

Soil C supplies vary spatially within and among riparian wetlands. Understanding this variability is essential to assessments of C‐dependent riparian wetland functions such as water quality enhancement and C storage. In this study, we examined the distribution of C with depth across the riparian landscape. Our objectives were to describe the spatial distribution of various C forms in the subsurface of riparian wetlands, and to identify the watershed, landscape, and soil characteristics that govern the distribution of these forms. Twenty‐two riparian sites, mapped as alluvial or outwash soils, were examined along first‐ through fourth‐order streams. Soils were described from pits and auger borings along transects established perpendicular to the stream. Roots and buried A horizons represent the majority of C in the subsurface, representing an important source of C for riparian zone functions. Buried A horizons and C‐rich lenses, indicative of alluvial soils, were identified in 21 of the 22 sites. Higher order riparian zones tended to have greater quantities of alluvium. Roots were generally distributed to the greatest depths close to the streams where alluvial deposits were thickest. All first‐, second‐, and third‐order riparian zones were mapped as outwash soils on county‐scale soil surveys. These sites, however, contained predominantly alluvial soils, suggesting that soil surveys at the 1:15,840 scale are inadequate for identifying alluvial soils along lower order streams. To assess the best predictors of alluvium distribution within riparian zones, 11 watershed characteristics were examined. A forward stepwise regression revealed that watershed size and floodplain width are two of the most important indicators of the quantity, width, and depth of alluvium, and subsequently subsurface C, within glaciated riparian zones.

MORPHOLOGY AND CHARACTERIZATION OF SOILS FORMED IN MARLBORO CLAY REGOLITH

The Marlboro Clay is a late Paleocene/early Eocene geologic formation that outcrops in significant portions of Prince George's County, Maryland. The formation exhibits slope instability and is unsuitable for most building structures. In this study, we describe and characterize the mineralogical and shrink-swell properties of soils formed in Marlboro Clay regolith. Samples were collected from 2 pits, 7 deep cores, and 38 1-m surface auger borings, five of which were collected at the same site as the deep cores. Potential volume change, particle size, and pH value were analyzed on all samples. X-ray diffraction scans were performed on selected samples. Mineralogical analysis indicated that the clay fractions of surficial samples were from approximately 10 to 50% smectite. However, the swell index values resulting from the potential volume change analysis were generally moderate for soil samples (most samples were less than 18,000 kg m -2 ). Deep cores generally had greater swell index values (mean, 21,205 kg m -2 ) than did surficial samples, indicating that pedogenesis reduces the shrink-swell capacity of these soils. Air-dried pH values were less than 4.0 in many samples, with a minimum of 2.7, indicating sufficient infilling of sulfide-bearing glauconitic sediments from underlying and overlying formations to cause sulfuricization upon oxidation. The pedogenesis of Marlboro Clay materials reduces their shrink-swell potential, although these soils may still be problematic for slope instability and construction because of low permeability.

Archaeological Testing at 41BP679, Bastrop County, Texas

During the spring of 2006 (May 11 through May 18, 2006), the Center for Archaeological Research (CAR) at The University of Texas at San Antonio conducted testing at 41BP679, a site formally listed as a State Archaeological Landmark. Site 41BP679 is located in Bastrop County at the confluence of the Colorado River and Spring Branch Creek, one of its tributaries. The site is on land that is the proposed location for the City of Bastrop Wastewater Treatment Plant. The installation of outflow pipes will impact the northern portion of 41BP679. The testing was conducted under Texas Antiquities Permit No. 4117, with Kristi Ulrich serving as Principal Investigator and Cynthia Moore Munoz serving as the Project Archaeologist. The testing involved mechanical auger borings, backhoe trenching and the hand-excavation of a limited number of test units. Testing confirmed that 41BP679 is likely to be a single component site (30-70 cm below surface) dating from the Paleoindian to Archaic period. One temporally diagnostic artifact, a Clear Fork tool, was recovered. Testing efforts failed to encounter features, and the low density cultural materials consist primarily of lithic debitage, burned rock and a handful of lithic tools. A detailed debitage analysis of the samples from the site suggests that the debitage collection represents a focus on tool production. The low density cultural remains have been impacted by bioturbation and vegetation clearing or plowing and their research potential is limited. The portion of the site tested during the investigations reported herein, along with the materials recovered, do not contribute to the State Archeological Landmark eligibility of 41BP679. We therefore recommend that the planned construction be allowed to proceed. We also recommend that the portion of the site located to the south of the area tested by CAR remain protected. The Texas Historical Commission (THC) concurred with the conclusions and recommendations reached by the CAR. In addition, the THC requested that the portion of 41BP679 not assessed by CAR be protected from potential construction-related impacts by a fence. The desired location of the fence would be furnished by CAR to insure that intact portions of the site are not adversely affected by the fence’s construction. Furthermore, if significant archaeological deposits are uncovered during plant construction, the THC requested that all work should stop in those immediate areas and the City of Bastrop should immediately contact the THC. CAR staff informed the City of the THC request. City

Archaeological Testing at 41BP678, Bastrop County, Texas

During the spring of 2006 (April 27 through May 4, 2006), the Center for Archaeological Research (CAR) at The University of Texas at San Antonio conducted testing at 41BP678, a site formally listed as a State Archaeological Landmark. Site 41BP678 is located in Bastrop County at the confluence of the Colorado River and Spring Branch Creek, one of its tributaries. The site is on land that is the proposed location for the City of Bastrop Wastewater Treatment Plant. The installation of outflow pipes and the excavation of a 500-foot deep water well and associated utilities installations will impact the central and eastern portions of 41BP678. The testing was conducted under Texas Antiquities Permit No. 4117, with Kristi M. Ulrich serving as Principal Investigator and Antonia L. Figueroa serving as the Project Archaeologist. The testing involved mechanical auger borings, backhoe trenching and the hand-excavation of a limited number of test units. Testing confirmed that 41BP678 is a multi-component site, with a Late Prehistoric presence in the upper 40 cm of the site, and a second component (40-80 cm below surface) of unknown temporal affiliation. Testing efforts failed to encounter features, and the low-density cultural materials consist primarily of lithic debitage and fire-cracked rock. A detailed debitage analysis of the samples from the two components suggests that the Late Prehistoric debitage collection represents a focus on tool production while the underlying component resembles an assemblage focused more on core reduction. This pattern suggests that site activities may have changed over time. The low-density cultural remains have been impacted by bioturbation and vegetation clearing or plowing and their research potential is severely limited. CAR recommends that the portion of the site tested during the investigations reported herein, along with the materials recovered, do not contribute to the State Archeological Landmark eligibility of 41BP678. We therefore recommend that the planned construction be allowed to proceed. We also recommend that the portion of the site located to the south of the area tested by CAR remain protected. All artifacts collected during this project are curated at the Center for Archaeological Research according to Texas Historical Commission guidelines.

Identification of facies models in alluvial soil formation: The case of a Swiss alpine floodplain

This paper describes different conceptual facies models intervening in alluvial soil formation in the case of the Sarine River floodplain, a partially embanked floodplain situated in the northwest of the Swiss Alps. Alluvial soils are submitted to processes of deposition and erosion and exhibit various characteristics reflecting the composition and properties of the material transported. Moreover, these processes of sedimentation and erosion vary in space and time and contribute thus to the heterogeneity of the whole floodplain system. Detailed analyses of the different soil layers permit a precise description of the variability and complexity of soil formation. In addition, the vertical succession of the horizons is useful to reconstruct the different natural or artificial events that occurred in this alluvial valley since the nineteenth century. On a larger scale, this study aims to contribute to floodplain management by identifying zones for restoration. The investigation was undertaken using data from 109 auger borings carried out in the Sarine River valley. Several morphological attributes of the different horizons and of the different profiles were first reduced in number and then grouped by a hierarchical agglomerative clustering. Profile factors were analysed by means of correlation analyses as well as other data summaries. The results showed positive correlations between several factors, particularly between the total profile thickness and the number of horizons found in the profile. Four facies models of alluvial soil formation are then proposed to illustrate and explain the variability of alluvial soil formation in the Sarine floodplain. Finally, these facies models are placed into the context of the Sarine floodplain scale case, according to the levels of organization of the alluvial system.

National Register Eligibility Testing of Site 41BO184, Brazoria County, Texas

Site 41BO184 is located within the right-of-way for the proposed expansion of State Highway 35 at the Oyster Creek crossing in southern Brazoria County. It was originally recorded as a multicomponent site in 1994 and was the subject of three distinct and limited archeological investigations by Texas Department of Transportation (TxDOT) staff. In 2003, TxDOT contracted with the Center for Archaeological Research (CAR) of The University of Texas at San Antonio to test the National Register of Historic Places and State Archeological Landmark eligibility of the site. Systematic mechanical auger borings, ten hand-excavated 1-x-1-meter test units, and Gradall scrapings helped identify a very sparse Late Prehistoric, possibly Rockport, component at the site. Although it is possible that at least some of the prehistoric artifacts come from the shell-paved driveway that cross-cut the site, it is also possible that some of the prehistoric artifacts represent in situ finds. The historic component, rich in temporally diagnostic ceramic fragments, dates to the mid-nineteenth century. The lack of intact features, the small size of the artifact assemblage, and the reduced size of the available materials, severely limits the research potential of the site. Therefore, it is recommended that site 41BO184 is not eligible for listing on the National Register of Historic Places nor does it warrant designation as a State Archeological Landmark.

Fuzzy continuous classification and spatial interpolation in conventional soil survey for soil mapping of the lower Piave plain

Soil maps on a reconnaissance or semi-detailed scale are frequently used as the basic level of information for regional land use assessment. However, they are impractical for suitability predictions concerning quality crops, which require an enlargement of details that can be guaranteed only by detailed soil survey and mapping. The change of scale increases the importance of field observations and introduces in the soil-landscape model the fuzziness related to surveyor's subjective judgement. The present study explored the applicability of the fuzzy c-means approach to conventional soil surveys for detailed land use assessment with the purpose of taking into consideration the fuzziness of data collected in areas where soil type transitions are not easily observable on the surface. The investigation was done using data from 1888 auger borings of a 42 000-ha survey carried out in the lower part of the fluvial plain east of Venice on the 1:25 000 map scale. The morphological quantitative attributes of the master horizons A, Bw, Bg, Bk and C were first reduced in number so as to remove attribute redundancy. They were then submitted to fuzzy c-means, testing cluster validity with both internal and external criterion measures. The best partition was obtained with four classes, which were consistent with the main soil-forming processes of the area not only in terms of class centre features, but also of spatial variability and distribution pattern of the class memberships. The investigated approach might represent part of a complex analytical sequence capable of using both the spatial distribution of fuzzy continuous classes and the landform analysis to formulate a spatially detailed territorial model representing the basic level of information for a locally oriented land use assessment.

Archeological and Geoarcheological Survey of State Highway 35 between Angleton and Old Ocean, Brazoria County, Texas

During March through July 2003, The Center for Archaeological Research of The University of Texas at San Antonio conducted a cultural resources survey, including geoarcheological studies, along portions of State Highway 35 from Angleton to Old Ocean in Brazoria County, Texas. This survey was conducted under Texas Antiquities Permit No. 3091 and was performed for the Texas Department of Transportation, Environmental Affairs Division. During the early phases of the survey, a Historic Context for the project was developed by Hardy-Heck-Moore, Inc. of Austin, Texas. This Historic Context was used to guide the latter phases of the survey, and is reproduced in this document. The project area consisted of a 15-mile-long discontinuous portion of the highway, with variable widths and eight separate detention ponds, varying in area from 2–12 acres each. Nearly 600 auger borings, here substituted for shovel tests, and 176 backhoe trenches were excavated, encountering no significant cultural deposits or features. The artifacts uncovered during these investigations were of recent origin and, therefore, none were collected for analysis and curation. With the exception of testing at site 41BO184, this project completes the cultural resources inventory of the State Highway 35 corridor between Angleton and Old Ocean.

Détection par méthode radar de niveaux anthropiques du Néolithique final sous le niveau actuel du lac de Chalain (France)

Several GPR profiles arc carried out on Lake Chalain (Jura) in order to detect several anthropic layers dating from Middle Neolithic times. The geometry of the sedimentary deposits is imaged by several GPR reflectors. Several auger borings allow the GPR reflectors to be correlated with anthropic levels (strata interleafed within lacustrine chalk). In particular, the oldest and finest (5 cm) level (of Horgen culture from the 32nd century BC) is detected. This experiment proves that it is possible to characterize the 3-dimensional geometry of the deposits from Lake Chalain built up in Middle Neolithic times.

Sur l'intégration de résultats géophysiques avec des résultats de sondages mécaniques ponctuels.

In archaeological survey, geophysical prospecting is a turning point among the methods of archaeological study, after the gathering of primary data and the specific means that are archaeological excavations. Several sites have been studied in the purpose of archaeological evaluation through geophysics and local mechanical tests with an auger or a dynamic penetrometer or a spade. Mechanical data are integrated with the geophysical ones for two kinds of processes. The first kind is the checking of anomalies by mechanical tests after the completion of the geophysical study : on a potters workshop (susceptibility survey and auger boring), on a prehistorical site (resistivity pseudo-section and penetration testing) and on a gallo-roman she (resistivity survey and spade test). The second kind corresponds to mechanical tests that have been carried out before or independently of the geophysical survey, on a prehistorical site (penetration tests and resistivity maps at different investigation depths) and on a gallo-roman site (auger borings and resistivity map). Methodological conclusions are inferred from these experiments.

Depositional patterns following the 1870s avulsion of the Saskatchewan River (Cumberland Marshes, Saskatchewan, Canada)

ABSTRACT The avulsion of the Saskatchewan River (Cumberland Marshes, east-central Saskatchewan, Canada) has resulted in new floodplain deposition over an area of more than 500 km2 since beginning in the 1870s. The avulsion deposits are predominantly fine grained and could be otherwise classifiable as sediments in alluvial floodplains presumed to be supplied by intermittent flooding of dominant master channels. The North Angling and Cadotte channels are older pre-existing channels that were intercepted and appropriated by the expanding avulsion. Following annexation of the North Angling Channel, stable cohesive banks inhibited channel enlargement and crevassing, forcing the increasing discharges to be accommodated by overbank flow and in the process, enhancing new levee aggradation. These levee deposits coarsen upward and thin downstream as a result of greater competence and higher proximal deposition rates brought on by the larger flows. In contrast, the Cadotte Channel responded to increasing discharges by levee breaching, giving rise to splay progradation and floodbasin filling. The Cadotte splay complex, formed from the avulsively annexed Cadotte Channel, represents a small but typical area of the avulsion belt. Facies characteristics and interrelationships examined from auger borings and vibracores are presented to illustrate patterns of deposition and floodplain development. Avulsive flooding initially raised local water-surface elevations, deepening small existing lakes and creating new shallow (1-2 m deep) lakes on the floodplain surface. Deposition began when levees of the Cadotte Channel were breached, allowing water and coarser sediment to spread as sheet-like flows while finer sediment was carried and deposited farther into the basin. Later, as the proximal splay sheets coalesced and grew basinward, flows became channelized, and progradation of mouth bars into marshes and shallow lakes, together with deposition of interchannel fines, became dominant, forming coarsening-upward sequences. Further floodplain aggradation developed by overbank flooding when splay channels became stabilized and bordered by levees. Gradual abandonment was accompanied by deposition of organic-rich fine-grained sediment on top of the progradational sequences. Throughout the avulsion, the North Angling Channel has stood as an older alluvial ridge separating two broad areas of avulsive deposition. Its recent levee deposits now grade basinward into these new floodplain sediments composed of thicker heterogeneous, predominantly upward-coarsening, and rapidly deposited facies of the avulsion.

Subsurface Exploration Using Bucket Auger Borings and Down-Hole Geologic Inspection

The down-hole geologic inspection of 24 in. bucket auger borings has been a hands-on technique for collecting valuable geologic structural and lithologic detail in southern California investigations for over 35 yr. Although it has been used for all types of investigations for hillside urban development, it is of particular benefit in landslide investigations and evaluations. It has also been successfully used in fault investigations where trenching could not get deep enough to intercept the faults. The benefits of down-hole geologic inspection during detailed mapping of large landslide complexes with multiple slide planes are discussed in this paper. This paper is the result of numerous requests by city engineers, who have been faced with the monumental task of approving or disapproving urban development on ancient landslides within their jurisdictions. (Many of these areas have the best views.) Many of the geotechnical investigations of these massive landslide complexes have been very limited in their determinations of accurate landslide parameters and very deficient in proper engineering analysis while based upon this limited data. This has resulted in many cases where the geotechnical consultant erroneously concludes that ancient landslides don9t move and it is alright to build upon them, even though they have neither justified the landslide parameters, nor the slope stability or safety. In these cases, there was also no redundancy-in-design due to considering future landscape watering, future rainfall, and future earthquakes. These are a common problem throughout large portions of California and other mountainous states. Because this author and the many consultants contacted during the preparation of this paper were not aware of other publications regarding this method of collecting detailed geologic data, this author included the safety considerations, safety equipment, the cost and the Cal OSHA requirements for entering exploration shafts.

Screened Auger Sampling: The Technique and Two Case Studies

AbstractThe screened auger is a laser‐slotted, hollow‐stem auger through which a representative sample of ground water is pumped from an aquifer and tested for water‐quality parameters by appropriate field‐screening methods. Screened auger sampling can be applied to ground water quality remedial investigations, providing:(1) a mechanism for determining a monitoring well's optimal screen placement in a contaminant plume; and (2) data to define the three‐dimensional configuration of the contaminant plume.Screened auger sampling has provided an efficient method for investigating hexavalent chromium and volatile organic compound contamination in two sandy aquifers in Cadillac, Michigan. The aquifers approach 200 feet in thickness and more than 1 square mile in area. A series of screened auger borings and monitoring wells was installed, and ground water was collected at 10‐foot intervals as the boreholes were advanced to define the horizontal and vertical distribution of the contaminant plumes. The ability of the screened auger to obtain representative ground water samples was supported by the statistical comparison of field screening results and subsequent laboratory analysis of ground water from installed monitoring wells.

Static cone tests and settlement of calcareous desert sands

The results of a recent in situ testing program to establish standard penetration test – cone penetration test (SPT–CPT) correlation for the windblown calcareous desert sands of Kuwait are presented and analyzed. The program consisted of auger borings and static cone tests at five sites along a 35 km long corridor. The resulting correlation was employed for prediction of the allowable soil pressure of footings at seven sites in Kuwait where load tests were carried out on square concrete footings placed at a depth of 1 m below ground surface. A comparison of the measured to the predicted soil pressures using the Schmertmann method indicated very close agreement. The average ratio of measured to predicted soil pressure is 93% for the seven test sites. Recommendations are made for further testing to determine the long-term settlement components due to creep and cyclic loading. Key words: load tests, sands, footings, allowable pressure, settlement, field tests, borings, cone penetration tests.