Using Drilling Data to Derive Geotechnical Properties of Variably Cemented Materials

The cone penetration test (CPT) is one of the most widely used tools for many applications in geotechnical engineering. Recognizing the importance of the CPT in geotechnical engineering, field-testing programs were conducted at five of the National Geotechnical Experimentation Sites (NGES) with funding from the Federal Highway Administration. The objective was to provide the NGES users with a CPT database with cone penetrometers of different sizes and functions. The availability of well-docwnented CPT tests to NGES users will help in developing and validating new methods for a wide range of geotechnical applications. In this paper, analyses of cone and piezocone penetration tests conducted at the NGES at Texas A&M University-clay site are presented. One novel test conducted at this site is the continuous intrusion miniature cone penetration test using the 2-cm 2 miniature penetrometer. The cone penetration tests were used to classify the soil and identify its -stratigraphy using different methods of interpretation. The probabilistic region estimation and fuzzy methods showed refined soil classification and quantified the different soil constituents (clay, silt, and sand) with depth. The 2-cm 2 miniature cone penetrometer detected finer soil stratification compared to the 10-cm 2 standard cone penetrometer. The CPT and piezocone penetration test (PCPT) results were used to evaluate soil properties such as the undrained shear strength and the overconsolidation ratio and results showed agreement with conventional test results.

This paper presents a method of evaluation of the state of cohesionless soil from the results of cone penetration and pressuremeter tests. This method is based on the comparison of the solutions to the cylindrical and spherical cavity expansion problems obtained by the authors with experimental results available in the literature on cone penetration and pressuremeter tests in large calibration chambers. The solutions to the cavity expansion problems are obtained with the use of a constitutive equation of hypoplasticity calibrated for the same soils as in the experiments. The pressure-expansion curves from pressuremeter tests are compared with those calculated for the expansion of a cylindrical cavity. The relation between the cone resistance measured in cone penetration tests and the limit pressure calculated for a spherical or a cylindrical cavity is established through a shape factor. Soils with similar granulometric properties are found to exhibit a common shape factor as a function of the pressure-dependent relative density. Key words: cone penetration test, pressuremeter test, cavity expansion, hypoplasticity

Studies in recent decades demonstrate the significant effect of stress configuration (e.g., vertical stress and lateral confinement) on the shear strength or, in this study, the cone penetration test (CPT) results. Addition of a surcharge over the ground changes the stress condition, and consequently, the CPT tip resistance. In this study, the results of different CPTs conducted before and after backfilling with various thicknesses in a land development project were reviewed while focusing on the trend of an increase in CPT penetration resistance due to the additional surcharge. Both pre- to post-fill stress ratios and soil type affect the rise in corrected {q}_{c} values after backfilling. Moreover, there has always been a sudden increase in {q}_{c} values around the pre-fill surface in all studied cases. In this study, another approach was derived from the reanalysis of CPT data from a specific site for predicting the post-fill corrected {q}_{c} from pre-fill results by considering the above-mentioned factor. Likewise, post-fill results were predicted by depth-normalized pre-fill CPT results using Robertson’s normalization method. The proposed approach in this study showed a better match with the site data compared to the normalization method, especially at and around the pre-fill surface.

Tailings, being mixtures of water and soil-sized particles, and sometimes air, are waste products generated by mining. They are stored on sites, often contained by embankments, forming what are known as tailings storage facilities (TSFs). Assessments of the state and strength of tailings inside a TSF may involve in situ tests, especially the cone penetration test (CPT) and occasionally the pressuremeter test (PMT). Cavity expansion theory may assist the interpretation of these tests. The coexistence of air and water in the pore space means the tailings is unsaturated and gives rise to a suction. The suction, and the extent to which air and/or water can drain through the pores, affects the cavity expansion results as well as CPT and PMT results. The cavity expansion problem is solved here considering four possible drainage conditions, constant suction, constant water mass, constant contribution of suction to the effective stress, and a constant air and water mass (closed system). It is reasoned that solutions for a closed system are relevant to the interpretations of CPTs and PMTs when < 15 % of the tailings volume is occupied by air, and that the constant effective stress condition (which is a close approximation to a constant water mass condition) is relevant when larger air volumes are present. By considering CPT data it is observed that linear proportionalities exist between effective cone penetration resistances and cavity wall pressures. The cavity expansion results are then converted to equivalent CPT results and used to construct charts which relate the normalised cone penetration resistance to the initial state parameter. The charts have use for unsaturated conditions and a variety of air volume fractions, as well as saturated conditions when the cone penetration rate is slow enough so drained conditions prevail or fast enough so that undrained conditions prevail.

Sensitive marine clay in Ottawa is a challenging soil for geotechnical engineers. This type of clay behaves differently than other soils in Canada or other parts of the world. They also have different engineering characteristic values in comparison to other clays. Cone penetration testing in sensitive marine clays is also different from that carried out in other soils. The misestimation of engineering characteristics from cone penetration testing can result. Temperature effects have been suspected as the reason for negative readings and erroneous estimations of engineering characteristics from cone penetration testing. Furthermore, the applicability of correlations between cone penetration test (CPT) results and engineering characteristics is ambiguous. Moreover, it is important that geotechnical engineers who need to work with these clays have background information on their engineering characteristics. This thesis provides comprehensive information on the engineering characteristics and behaviour of sensitive marine clays in Ottawa. This information will give key information to geotechnical engineers who are working with these clays on their behaviour. For the purpose of this research, fifteen sites in the Ottawa area are taken into consideration. These sites included alternative technical data from cone and standard penetration tests, undisturbed samples, field vanes, and shear wave velocity measurements. Laboratory testing carried out for these sites has resulted in acquiring engineering parameters of the marine clay, such as preconsolidation pressure, overconsolidation ratio, compression and recompression indexes, secondary compression index, coefficient of consolidation, hydraulic conductivity, clay fraction, porewater chemistry, specific gravity, plasticity, moisture content, unit weight, void ratio, and porosity. This thesis also discusses other characteristics of sensitive marine clays in Ottawa, such as their activity, sensitivity, structure, interface shear behaviour, and origin and sedimentation. Furthermore, for the purpose of increasing local experience with the use of cone and ball penetrometers in sensitive marine clays in Ottawa, three types of penetrometer tips are used in the Canadian Geotechnical Research Site No. 1 located in south-west Ottawa: 36 mm cone tip, and 40 mm and 113 mm ball tips. The differences in their response in sensitive marine clays will be discussed. The temperature effects on the penetrometer equipment are also studied. The differences in the effect of temperature on these tips are discussed. Correlations between the penetrometer results and engineering characteristics of Ottawa's clays are verified. The applicability of correlations between the testing results and engineering characteristics of sensitive marine clays in Ottawa is also presented in this thesis. Two correlations from the Canadian Foundation Engineering Manual are examined. One of these correlations is between the N60 values from standard penetration testing and undrained shear strength. The other correlation is between the shear wave velocity measurement and site class. Temperature corrections are suggested and discussed for penetrometer equipment according to laboratory calibrations. The significance of the effects due to radical temperature changes in Canada and Ottawa is discussed. Some of the main findings from this research are as follows. • The Canadian Foundation Engineering Manual presents a correlation between standard penetration tests (SPTs) and the undrained shear strength of soils. This relationship may not be applicable to sensitive marine clays in Ottawa. • Another correlation between the site class, shear wave velocity, and undrained shear strength is presented by this same manual which may not be applicable to sensitive marine clays in Ottawa. • The rotation rate for field vane testing as recommended by ASTM D2573 is slow for sensitive marine clays in Ottawa. • Correction factors applied to undrained shear strength from laboratory vane tests may not result in comparable values with the undrained shear strength obtained by using field vane tests. • Loading schemes in consolidation or oedometer testing may affect the quality of the targeted results. • Temperature corrections should be applied to penetrometer recordings to compensate for the drift in the results of these recordings due to temperature changes. • The secondary compression index to compression index ratio presented in the literature may not be the value obtained from this research.

Eli Lilly and Company are investing $4.5 billion to create the Lilly Medicine Foundry, a new center for advanced manufacturing and drug development, combining research and manufacturing in a single location. The Medicine Foundry will be located in Indiana's LEAP Research and Innovation District in Lebanon, Indiana and will expand the company's investment there to more than $13 billion. Multiple new facilities are planned for the manufacture of Petides (short chains of amino acids that are involved in many physiological processes and biochemical functions), Oligonucleotides (short chains of nucleotides that can be made of DNA or RNA) and Small Molecules (molecules with a molecular weight of &lt; 900 Da) with a Central Utility Building (CUB) and an extensive array of pipe and utility racks to support all of the manufacturing facilities. The facilities are being constructed on pads of structural fill approximately 10-ft to 15-ft above the natural ground surface. Native soils are generally up to 35 feet of soft to stiff alluvial soil with stiff to very hard glacial deposits underlying the site. Column loads for manufacturing facilities typically ranged from 400 to 1000 tons with 4000 psf design bearing pressures for large floor areas in most of the facilities to accommodate the relatively heavy manufacturing equipment at each facility. Project requirements include a maximum of 3/4 in total settlement of the structures. Given the size and overall weight of the structures and the large area loads of the manufacturing equipment within the structures, this specification became the primary design consideration for foundation support of the majority of the structures. The manufacturing facilities will be supported on a combination of Augered-Cast-in-Place (ACIP) piles under building columns and augered, Rigid Inclusions (RIs) under the floors. The CUB facility will be supported by a range of augered, Rigid Inclusions under columns and floors depending on the required support across the facility. To date, approximately 6,500 ACIP piles and 4,700 RIs have been installed to support these facilities. This paper addresses the design and construction of the referenced ACIP piles and RIs with particular regard to the behavior of the foundation elements in the glacial till deposits underlying the site. Geotechnical site characterization information included logs of several borings and the results of cone penetration tests (CPT) performed to up to 100-ft below grade across the entire project site. The boring logs included visual classifications and Standard Penetration Test (SPT) results. Results of laboratory tests performed on collected samples were also included in the report. The results of several seismic CPTs were also provided. The shear wave velocity profile information indicated stiffnesses in the till deposits that were significantly greater than might be indicated by the CPT and boring data. The anticipated soil stiffnesses were verified by the pile and RI element performance testing program, allowing the project team to economize the foundation design for pile capacity, but more significantly for the estimation of overall structure settlement. Soil stiffness was additionally verified using the Automated Monitoring Equipment on board the pile and RI installation platforms (or Measurement While Drilling, MWD) to verify the stratigraphy encountered during foundation installation.

The use of the cone penetration test (CPT) for offshore soil investigations is particularly important in sands where it proves problematic and often impossible to take undisturbed samples. CPT data can provide reliable indications of in situ soil properties and/or in situ stress conditions. The geotechnical literature, however, abounds with different procedures for interpreting CPT data in sands. A comprehensive data base for sands was established mainly from large scale calibration chamber tests performed at several institutions. The data base also included results from field tests described in the literature and from NGI's experience. The paper presents an evaluation and updated recommendation of Schmertmann's method for estimating relative densities from recorded cone resistance. It also evaluates various procedures for interpreting the drained friction angle from cone resistance and presents correlations between the constrained deformation modulus and cone resistance. Finally, the paper recommends other in situ tests to complement and enhance the interpretation of CPT data in sand, and points out the necessity for simultaneous sampling and laboratory testing. INTRODUCTION The use of the cone penetration test (CPT) is particularly important in sands where it proves problematic and often impossible to take undisturbed samples. However, the complex mechanism of continuous penetration of a cone into a soil is very difficult to model theoretically. Therefore theoretical relationships modified with empirical data have often underlain the interpretation of CPT results in terms of engineering parameters. Purely empirical relationships are also widely used. In an attempt to clarify the cone interpretation methods in sands, Exxon Production Research Company initiated a study conducted at the Norwegian Geotechnical Institute (NGI) to evaluate and possibly update the existing procedures. Well documented references and NGI in-house research data from large calibration chamber laboratory tests have been synthesized to form consistent data sets of soil parameters and CPT results for several sand types. The data sets have been used to evaluate existing theories and correlations among CPT results and engineering parameters, mainly relative density, shear strength and compression modulus. Where appropriate, new or updated correlations have been developed. Although field tests represent more closely in situ behaviour, the present study considers predominantly cone penetrometer results from large calibration chambers, where test conditions and soil characteristics are better controlled than in situ and measured cone penetrations can be correlated to well controlled sand densities and geotechnical parameters from more conventional laboratory tests. Due to the emphasis placed on calibration chamber tests. These are described in more detail in the following chapter. LARGE CALIBRATION CHAMBER TESTS From 1975 to 1977, NGI carried out an extensive series of laboratory calibration tests on large sand samples using the electric friction cone penetrometer Similar investigations have been undertaken in Australia 2'3, in Florida 4t5 and in Italy.6,7 Calibration chamber tests enable the investigation of the cone penetrometer under laboratory conditions where one can carefully control and measure soil properties, stresses and strains.

This paper investigated the densification effects of deep dynamic compaction (DDC) and vibratory compaction on loose saturated sands, which were based on two well-documented case histories. This investigation was carried out by examining pre- and post-compaction cone penetration testing (CPT) results. The CPT results indicated that under the same design earthquake excitation, the sands treated by DDC were densified to the level of resisting potential liquefaction, while, the sands were still liquefiable after vibratory compaction.

Predicting ultimate axial bearing capacity of pile foundations is an important and complicated problem in geotechnical engineering. Cone penetration test (CPT) is a reliable in situ test widely used in the analysis and design of pile foundations. In this study, new CPT-based axial pile bearing capacity models are presented for both cohesionless and cohesive soils using evolutionary polynomial regression (EPR), a branch of evolutionary approaches. A relatively comprehensive database is gathered and divided into training and testing sub-sets to avoid over-fitting. This database includes both coarse and fine grain soils, cone tip resistance and sleeve friction of CPTs, geometry and bearing capacity of piles. The presented models are compared to some previously published ones and their preferences are demonstrated statistically and probabilistically. Proper applicability of the models in predicting axial pile bearing capacity is then confirmed by field verification, compared to analytical and empirical models available in the literature.

Comparative performance of the international piezocone and China CPT in Jiangsu Quaternary clays of China

Pore pressure and shear strength are two important parameters that control the stability of slopes. These parameters can be derived in-situ by cone penetration testing (CPT) with pore pressure measurements. This paper presents the results from three static, vibratory and dissipation CPT profiles deployed into a landslide headwall at Pyes Pa, Bay of Plenty, New Zealand. The landslide strata consist of volcanic ashes and ignimbrites. Studying the stability of slopes in this area using in-situ geotechnical testing is of societal-economic importance since several other landslides within comparable strata caused considerable property damage. Three CPT profiles were collected across the headwall of the slide scar with 2 m spacing in undisturbed sediments using static, vibratory and dissipation test modes. Static CPT results are used to evaluate soil grain size variations, geotechnical parameters of sediments such as shear resistance, probable slip surface and sensitivity of sediments. Liquefaction potential of sediments is assessed using vibratory CPT results. For dissipation tests, the cone remained stationary in the sediment for ∼60 min to monitor pore pressure dissipation at the depths of 6, 9 and 11 m. With the use of pore pressure dissipation data, values of soil horizontal permeability are calculated. The liquefaction probability from static CPT results is compared to liquefaction potential evaluation from vibratory CPT. Last but not least, an unstable soil layer is defined based on static CPT, vibratory CPT and dissipation results.KeywordsCPTLandslideStaticVibratoryDissipation

Accurate prediction of Standard Penetration Test (SPT) blow counts from Cone Penetration Test (CPT) data is critical for reliable geotechnical characterization, particularly when SPT data are scarce or difficult to obtain.This study presents a data-driven framework that employs an Artificial Neural Network (ANN) to estimate the corrected SPT blow number (N 60 ) using key CPT parameters.The database was compiled from two construction sites in Nasiriyah, Iraq, comprising cone tip resistance (q c ), sleeve friction (f s), and effective overburden pressure ( vo ) as input variables.Multiple ANN architectures were trained and validated, and optimal performance was achieved using one hidden layer with eight neurons, yielding a coefficient of determination (R 2 ) of 0.9967, and two hidden layers with six and sixteen neurons, achieving R 2 = 0.9976.Relative importance analysis indicated that cone tip resistance contributed 44% to the model's predictive strength, followed by sleeve friction and effective overburden pressure, each accounting for approximately 26%.Sensitivity analysis confirmed that N 60 increases with higher input parameters, consistent with soil behavior principles.The ANN model demonstrated high accuracy and generalization capability across both sandy and clayey soils.Design charts derived from the trained model enable practical estimation of SP T -N from CPT results, providing geotechnical engineers with a rapid and reliable tool for site characterization and preliminary design.

The compaction control of earth works is an essential task in geotechnical engineering. In order to build more sustainably and to reduce project costs, fine-grained materials are more often used for embankment construction nowadays. The quality control of compacted soil layers is usually defined in terms of deformation moduli obtained from static and dynamic plate load tests or based on the degree of compaction, which is generally related to the Proctor density. Penetration tests, such as cone penetration tests (CPT), seismic flat dilatometer tests (SDMT) or dynamic probings (medium heavy dynamic probings (DPM)), show a potential for assessing the compaction along vertical profiles but no standardized quality criteria have been elaborated yet. The present work investigates the effects of different water contents and degrees of soil stabilization on results of CPT, SDMT, DPM, plate load tests and Proctor tests for an 8 m high trial embankment, characterized by a clayey to silty material. CPT and DMT results were found to strongly correlate with deformation moduli of static and dynamic plate load tests, enabling the definition of new quality criteria for compaction control.

Earthquake-induced soil liquefaction (EISL) can cause significant damage to structures, facilities, and vital urban arteries. Thus, the accurate prediction of EISL is a challenge for geotechnical engineers in mitigating irreparable loss to buildings and human lives. This research aims to propose a binary classification model based on the hybrid method of a wavelet neural network (WNN) and particle swarm optimization (PSO) to predict EISL based on cone penetration test (CPT) results. To this end, a well-known dataset consisting of 109 datapoints has been used. The developed WNN-PSO model can predict liquefaction with an overall accuracy of 99.09% based on seven input variables, including total vertical stress (σv), effective vertical stress (σv′), mean grain size (D50), normalized peak horizontal acceleration at ground surface (αmax), cone resistance (qc), cyclic stress ratio (CSR), and earthquake magnitude (Mw). The results show that the proposed WNN-PSO model has superior performance against other computational intelligence models. The results of sensitivity analysis using the neighborhood component analysis (NCA) method reveal that among the seven input variables, qc has the highest degree of importance and Mw has the lowest degree of importance in predicting EISL.

This manual provides guidance on how to use the cone penetration test (CPT) for site investigation and foundation design. The manual has been organized into three volumes. Volume 1 covers the execution of CPT-based site investigations and presents a comprehensive literature review of CPT-based soil behavior type (SBT) charts and estimation of soil variables from CPT results. Volume 2 covers the methods and equations needed for CPT data interpretation and foundation design in different soil types, while Volume 3 includes several example problems (based on instrumented case histories) with detailed, step-by-step calculations to demonstrate the application of the design methods. The methods included in the manual are current, reliable, and demonstrably the best available for Indiana geology based on extensive CPT research carried out during the past two decades. The design of shallow and pile foundations in the manual is based on the load and resistance factor design (LRFD) framework. The manual also indicates areas of low reliability and limited knowledge, which can be used as indicators for future research.