Site Investigation Research Articles

Quantifying CPT cone factors in clays derived from weathered mudstone

The empirical interpretation of cone penetration test (CPT) cone factors ( N k ) can be subject to considerable variability for clays derived from weathered mudstones, leading to significant deviations in the estimation of undrained shear strength ( S u ). This paper presents a comparison of triaxial and CPT data from a site investigation in clays derived from weathered mudstones in central England. Corrected cone factors ( N kt,UU ) were derived from a one-to-one comparison of 94 pairs of unconsolidated, undrained triaxial and CPT data from equivalent depths. The performance of the cone factors was evaluated using a training set (75 pairs) and a test set (19 pairs). A parametric study was used to explore the variability of N kt,UU , quantified using the coefficient of variation (COV Nkt,UU ), for varied separation distance thresholds ( D s ) between individual triaxial and CPT data. The absolute deviation between the laboratory shear strength ( S u(Lab) ) and that predicted from CPT profiles (S u(CPT) ) was not sensitive to N kt,UU values in the range 25 < N kt,UU < 31. The parametric study showed that D s could be increased from 50 to 250 m, to include more data pairs for estimates of N kt,UU , without substantially increasing COV Nkt,UU .

Landslide susceptibility assessment in multiple urban slope settings with a landslide inventory augmented by InSAR techniques

Landslide susceptibility assessment (LSA) evaluates the likelihood of landslide occurrences and can help mitigate and prevent landslide risks. Recently, there have been vast applications of data-driven LSA methods owing to the increased availability of high-quality satellite data and landslide inventories. However, two issues remain to be addressed, as follows: (a) Items in a landslide inventory are mainly historical landslides from the interpretation of optical images and site investigation, resulting in predictive models trained with these items being insensitive to undetectable slope movements, such as slow-moving landslides that have not yet occurred; (b) Most study areas contain a variety of landslide-prone geographical settings that a single model can not accommodate well. Considering the complex landslide causes in Hong Kong with a land area of approximately 1108 km2, we proposed the utilization of multi-temporal InSAR techniques to generate weak landslide samples from slopes with ground surface movements for landslide inventory augmentation; and meta-learn intermediate representations for the fast adaptation of LSA models corresponding to different landslide-prone geographical settings. Besides, we performed feature permutation to identify dominant landslide-predisposing factors. The LSA results in Hong Kong revealed that slope deformation in several mountainous areas is closely associated with the occurrence of recorded landslides. By augmenting the landslide inventory using InSAR techniques, the proposed method enhanced the LSA models' capacity to identify slow-moving landslides and achieved better statistical performance. The discussion highlights that slope and stream power index (SPI) are the key landslide-predisposing factors in Hong Kong, but the dominant landslide-predisposing factors will vary under different geographical conditions. By comparison with the methods that treat LSA as a binary classification problem, such as support vector machine, multilayer perceptron, deep belief network, and random forest based LSA methods, the proposed method entails a fast-learning strategy and outperforms these methods in data-driven model evaluation indicators, e.g., by 3–6% in accuracy, 2–6% in precision, 1–2% in recall, 3–5% in F1-score, and approximately 10% in Cohen Kappa. The information about the relative importance of landslide predisposing factors, derived through feature permutation, can foster guidance for targeted landslide prevention schemes, such as constructing and maintaining slope consolidation facilities in areas where slope is the dominant landslide-predisposing factor.

Enhancing open clinical trials through blinded evaluations: an exploration with diabetic foot infections

BackgroundBlinding drugs through simulation techniques is an important means to control the subjective bias of investigators and subjects. However, clinical trials face significant challenges in the placebo production of drugs, and many trials cannot be double-blinded.ObjectiveThis study was conducted to ascertain the consistency between non-blind and blind evaluation results in clinical trials and to pioneer strategies to control information bias, particularly in trials where double-blinding is not feasible.MethodsIn this investigation, a randomized controlled trial (RCT) studying diabetic foot infections (DFIs) was utilized as a representative case. In this trial, the grading of DFIs, as per guidelines by the Infectious Disease Society of America (IDSA) and International Working Group on Diabetic Foot (IWGDF), was used as the primary efficacy indicator. A sample of sixteen patients was randomly chosen from the RCT, and DFI grading was assessed jointly by both non-blinded investigators and blinded center-reading investigators. A consistency test was then deployed to compare the evaluation results, forming the basis for our proposed strategies for effective blinded evaluation. In addition, other perspectives were collected at the end of this study, including with those involved in designing and conducting the recent blinded evaluation trial.ResultsFive subjects were excluded due to the quality of photos or the lack of post-treatment visits. The post-treatment IDSA/IWGDF grading results were compared in 11 subjects (experimental group=6, control group=5), and the consistency test showed inconsistent results between the non-blinded and center reading blinded evaluations (Kappa=0.248, p=0.384). In the experimental group, three cases were judged as grade 1 in the non-blinded evaluation and grade 2 in the central reading blinded evaluation; in the control group, three cases were judged as grade 2 in the non-blinded evaluation and grade 1 in the central reading blinded evaluation. The sum of these two cases in 22 post-treatment determinations was 27% (6/22). Furthermore, researchers propose several strategies for implementing blinded evaluations in clinical trials after this trial, which encompass aspects such as staff allocation, training, participant management, trial drug administration, efficacy indicator collection, and safety event management.ConclusionsThe study highlighted that evaluations from non-blinded site investigators may potentially exaggerate the efficacy of the experimental group and that deep wounds can present challenges for observation via center-reading photos. These findings underline the vital necessity for objective assessment in open clinical trials, especially those where wound observation serves as the primary efficacy indicator. The study suggests the adoption of independent blinded investigators at each site, complemented by a comprehensive set of standard operating procedures for blinding evaluation. These measures could serve as an effective counterbalance to subjective bias, thereby augmenting the credibility and consistency of results in open clinical trials. The implications of these findings and recommendations could be of great significance for the design and execution of future open clinical trials, potentially bolstering the quality of clinical research in this area.Trial registrationChiCTR2000041443. Registered on December 2020

A geological and geotechnical information system (GEO-GIS) for urban planning and its application to the Acıpayam Basin (Denizli, Turkey) with some observations from a M w 5.5 earthquake on 20 March 2019

There are many site investigation projects used for the urban planning of a city. They are archived in hard copy or scanned in image files stored on computers. In this study, geological, geotechnical and geophysical data obtained from different site investigation projects in the Acıpayam district were evaluated in the same coordinate system using a geological and geotechnical information system (GEO-GIS) computer program. The Acıpayam GEO-GIS database includes field tests in 82 boreholes, 85 observation pits, laboratory test results of soil samples, 99 seismic refraction measurements and 70 microtremor measurements. Required information from the database can be displayed at its spatial coordinates on a base map and new maps can also be drawn using the GEO-GIS database system. Resultant maps drawn using the Acıpayam GEO-GIS database show that in the northern and eastern parts of the Acıpayam district, where the Oğuz, Kırca, Yassıhöyük, Apa, Ovayurt, Karahüyük, Ucarı and Gedikli villages are located, weak soil layers exist. This means that some damage may be caused to adobe and masonry buildings in the villages during shaking associated with strong earthquakes, as observed after the 5.5 (M w ) earthquake that occurred on 20 March 2019. The Acıpayam GEO-GIS database system is a useful tool for engineers and planners that can assist in drawing GIS-produced maps for geotechnical evaluations of the basin. These maps can be used in decision-making projects for urban planning. Thematic collection: This article is part of the Leading to Innovative Engineering Geology Practices collection available at: https://www.lyellcollection.org/topic/collections/leading-to-innovative-engineering-geology-practices

Abstract 12495: Modes of In-Hospital Death in Patients With Cardiogenic Shock (CS): An Analysis From the Critical Care Cardiology Trials Network (CCCTN)

Introduction: Mortality from cardiogenic shock (CS), a syndrome of multi-organ system dysfunction, remains high. However, data regarding how patients with CS expire are limited and may have implications for designing clinical trials, identifying therapeutic strategies, and improving outcomes. Aim: We sought to describe primary modes of in-hospital death among patients admitted with CS to cardiac intensive care units (CICUs). Methods: CCCTN is a multi-national research network of advanced CICUs coordinated by the TIMI Study Group (Boston, MA). Using standardized definitions, site investigators classified the direct mode of in-hospital death for patients with CS. Categories included 8 possible modes of cardiovascular (CV) and non-CV death ( Fig ). Subgroups defined by cardiac arrest prior to CICU admission and use of mechanical circulatory support (MCS) were explored. Results: Among 1098 CS cases captured from 10/2021-09/2022, 358 (32.6%) died during the index hospitalization with a median time to death of 4.3 (Q1-Q3, 1.1-10.9) days from CICU admission. Among the deaths, 50%, 41%, and 9% occurred in the context of HF-CS, AMI-CS, and secondary CS, respectively. Overall, mode of death was CV in 82% of cases ( Fig A ). Refractory CS was the dominant mode of death (66%), followed by arrhythmia (13%), anoxic brain injury (6%), and respiratory failure (5%; Fig A ). Compared to patients without preceding cardiac arrest, those with cardiac arrest prior to CICU admission were more likely to die from anoxic brain injury (10% vs. 1%; p<0.01; Fig B ). Compared to patients managed without MCS, those with MCS were more likely to die from refractory shock (p<0.01), either cardiogenic (74% vs. 61%) or non-cardiogenic (6% vs. 3%; Fig C ). Conclusions: Most in-hospital deaths in patients with CS are related to direct CV causes, particularly refractory CS. However, there is potentially important heterogeneity in mode of death across subgroups defined by preceding cardiac arrest and use of MCS.

Characterization of Site Amplification by a Parametric Study

ABSTRACT The reliability of V s30 and the performance of alternative time averaged shear wave velocities (V sz ) and shear wave travel times (T tz ) at various depths, z, were investigated for the estimation of site amplification and fundamental frequency (f 0) characterization by considering the linear and nonlinear soil behavior. The study revealed that alternative parameters performed better than V s30 and the best performing z parameters changed by switching from convex to concave theoretical profiles and by increasing ground motions. For a practical usage in site investigations, guidelines to estimate nonlinear soil amplification factor and fundamental frequency from the linear ones were presented.

An Engineering Geological Appraisal of the Leakage Problem in Dora-1 Earthen Dam, Tigray: Implications for its Stability

Leakage is one of the major problems facing the functionality and sustainability of dams. It occurs through the embankment body, reservoir, foundation, and abutments. This study was conducted to identify the main causes of the leakage problem at the Dora-1 dam, located in the northern part of Ethiopia. It is an earthfill dam with a height of 43.5 m, crest length of 454 m, and reservoir capacity of 4.67 million cubic meters. Part of the embankment body was wet and swampy up to 20 m high from the ground due to leaking water. Geological investigation, laboratory test of the construction materials (including grain size analysis, specific gravity and water absorption, Atterberg limit, free swell, dispersion, permeability, and shear strength), and electrical resistivity investigation were used to identify and pinpoint the possible causes of the leakage problem. Results of the study show that the favorable geological features responsible for the occurrence of leakage include: (a) geological contact between sandstone and moderately to highly weathered basalt unit at the left abutment, (b) the gravelly sand deposit at the central foundation and (c) dyke outcrop at the river course within the reservoir running in the upstream-downstream direction. Results of laboratory tests for clay core show medium to high compressibility, good to poor workability, and semi-pervious to impervious permeability when compacted. The water absorption and the percentage finer of the filter material don’t satisfy the filter criteria and the shell material was found to be semi-previous. The anomalous in the resistivity survey result confirms the situation. Slope stability analysis of the embankment showed instability conditions at full reservoir level. Close follow-up and a downstream stabilization structure, including rock and gravel support, were recommended.
 Construction material; Embankment dam; Site investigations; Ethiopia.

Status of the Site Investigation and Site Selection Process for a Deep Geological Repository in Switzerland

Nagra, the National Cooperative for the Disposal of Radioactive Waste, in Switzerland, is realizing a project of the century: the planning, construction, operation, and closure of a deep geological repository (DGR) for the nation’s radioactive waste. The site selection process for a DGR is regulated by a three-stage process described in the Sectoral Plan, which the Federal Government approved in 2008. An overconsolidated shale, the Opalinus Clay, was selected as the most suitable rock formation as a result of Stage 2 of the Sectoral Plan. The three remaining siting regions were investigated in detail during Stage 3, including more than 12.5 km of exploratory boreholes drilled since 2018 and high-resolution, three-dimensional seismic surveys covering an area of approximately 250 km2. In September of 2022, Nagra proposed Nördlich Lägern as the preferred siting region for a combined repository in Northern Switzerland. Nagra plans to submit the corresponding general license application to the authorities by the end of 2024.

Endpoint adjudication in cardiovascular clinical trials.

Endpoint adjudication (EA) is a common feature of contemporary randomized controlled trials (RCTs) in cardiovascular medicine. Endpoint adjudication refers to a process wherein a group of expert reviewers, known as the clinical endpoint committee (CEC), verify potential endpoints identified by site investigators. Events that are determined by the CEC to meet pre-specified trial definitions are then utilized for analysis. The rationale behind the use of EA is that it may lessen the potential misclassification of clinical events, thereby reducing statistical noise and bias. However, it has been questioned whether this is universally true, especially given that EA significantly increases the time, effort, and resources required to conduct a trial. Herein, we compare the summary estimates obtained using adjudicated vs. non-adjudicated site designated endpoints in major cardiovascular RCTs in which both were reported. Based on these data, we lay out a framework to determine which trials may warrant EA and where it may be redundant. The value of EA is likely greater when cardiovascular trials have nuanced primary endpoints, endpoint definitions that align poorly with practice, sub-optimal data completeness, greater operator variability, and lack of blinding. EA may not be needed if the primary endpoint is all-cause death or all-cause hospitalization. In contrast, EA is likely merited for more nuanced endpoints such as myocardial infarction, bleeding, worsening heart failure as an outpatient, unstable angina, or transient ischaemic attack. A risk-based approach to adjudication can potentially allow compromise between costs and accuracy. This would involve adjudication of a small proportion of events, with further adjudication done if inconsistencies are detected.

Intelligent nuclear decommissioning solution: Code for site characterization and management of overall surveys

The site characterization should be conducted during the entire decommissioning period to verify the compliance with regulatory guidance and to demonstrate the safety for site release. A technical manual called Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) has been widely used as a reference for the site characterization. Historically, it has required enormous resources because of extensive data handling. And there is a possibility of a human error because of the expert’s judgement reliance. In this study, software called COde for Site characterization and Management of Overall Surveys (COSMOS) has been developed with Artificial Intelligence (AI) models. One of the AI model is possible to revolutionary reduce time for finding keyword related contamination, and the other manages database by digitalizing drawings. Also, other survey modules are possible to conduct related all of statistical tests. In the end, COSMOS would be utilized as a total management solution for site characterization.

Challenges and Lessons Learnt Learned from Industry-Driven Multi-Centre Global Clinical Trials in IgA Nephropathy (IgAN): Site Investigators' Perspective

Challenges and Lessons Learnt Learned from Industry-Driven Multi-Centre Global Clinical Trials in IgA Nephropathy (IgAN): Site Investigators' Perspective

Exploring the role of decentralized clinical trials in oncology: Insights from cancer centers.

105 Background: Decentralized clinical trials (DCT) involve conducting some or all trial-related activities at a location separate from the investigator's site. DCT can help reduce the burden on patients, sites, and sponsors while improving patient accrual and retention rates and increasing the diversity of trial participants. While DCT methods provide patient-centric trial flexibilities, they can impact trial operations. This survey aimed to gain insights into the perspectives and experiences of cancer centers regarding DCT in the field of oncology. Methods: A 13-question survey that addressed prior experience, perceived benefits, and challenges in implementing DCT was developed by members of the Association of American Cancer Institutes (AACI) Clinical Research Innovation (CRI) Steering Committee. The survey was sent via email to the AACI CRI listserv, which consists of members of 90 cancer research centers in North America. Respondents were asked to consider their activity related to treatment and non-treatment interventional trials. Results: There were 75 total responses from members affiliated with 55 individual cancer centers. Of these centers, 73% were NCI-designated cancer centers. Of the individual respondents, 57% were clinical trial office administrators. The issues of highest concern by respondents were 1) meeting study timelines, 2) patient recruitment and 3) cost (83%, 65%, 44% respectively). All respondents had prior experience with DCT tools with the most common components being the use of local facilities for labs/imaging, telemedicine and e-consent (89%, 69%, 68% respectively). The areas of most perceived benefit from DCT include reduced participant burden, increased diversity and participant retention (81%, 80%, 68% respectively) while areas of perceived challenges include quality control, regulatory compliance and cost (61%, 59%, 49% respectively). While 92% respondents agreed/strongly agreed that DCT can improve clinical trial access, 92% agreed/strongly agreed that additional site staff training is required for successful DCT implementation. Conclusions: DCT tools have been widely implemented in oncology trials with all surveyed sites reporting prior experience. This survey emphasizes the perceived benefits of DCT in oncology, while underscoring the importance of addressing challenges and meeting the specific requirements of cancer centers. Future work should identify specific areas that require additional staff training to enable DCT readiness.

Metal-organic framework-derived cation regulation of metal sulfides for enhanced oxygen evolution activity

Heteroatom doping serves as an important strategy to improve the oxygen evolution reaction (OER) activity of transition-metal compounds, while the investigation of intrinsic active sites and mechanisms remains insufficient. In this work, a facile cation regulation strategy is reported to boost the OER activity of metal sulfides via pyrolysis of the Ni-Co bimetallic metal-organic framework. The obtained Ni-substituted CoS nanoparticles on nitrogen-doped mesoporous carbon (Ni-CoS/NC) catalyst achieves a current density of 10 mA cm−2 at a small overpotential of 270 mV with a Tafel slope of 37 mV dec−1 in 1.0 mol L−1 KOH. Through a combination of spectroscopy study and theoretical computations, the activity origin is revealed at the atomic level. The CoxNi1–xOOH serves as the real active site for the OER generated by the Ni-CoS/NC reconstruction under oxidation potential during OER. The Ni substitution results in a strong electronic interaction between the two metals, thus generating more negatively charged Co atoms and more positively charged Ni atoms in the electrocatalyst. The metal sites with regulated electronic structure exhibit enhanced surface adsorption of OOH* and reduce the OER overpotential. Meanwhile, the conductive porous carbon scaffold facilitates electron transfer, mass diffusion, and the accessibility of active sites. This work not only provides a feasible cation regulation strategy for the design of high-performance electrocatalysts for low-cost energy storage and conversion systems, but also yields fresh insight into the activity enhancement mechanisms and intrinsic active sites.

Improved resistance prediction and reliability for bridge pile foundation in shales through optimal site investigation plans

Improved resistance prediction and reliability for bridge pile foundation in shales through optimal site investigation plans

A CPT-Based Design Framework for Uplifted Open-Ended Piles Installed in Spatially Variable Sandy Soils. II: Implications to Site Investigation and Pile Design for Offshore Wind Farms

A CPT-Based Design Framework for Uplifted Open-Ended Piles Installed in Spatially Variable Sandy Soils. II: Implications to Site Investigation and Pile Design for Offshore Wind Farms

A Study on Previous Cases of Seismic Reflection Surveys for Deep Geological Disposal Site Investigations in Crystalline and Sedimentary Host Rocks

A Study on Previous Cases of Seismic Reflection Surveys for Deep Geological Disposal Site Investigations in Crystalline and Sedimentary Host Rocks

Application of a novel multi-criteria decision analysis approach for evaluating the sustainability of contaminated site management: An example from China

The performance of contaminated site management in terms of its sustainability can be inherently uncertain, considering that this performance depends not only on individual site characteristics and variability, but also on integrated (and potentially long-term) environmental, social, economic and technical impacts. The present study proposes a combination weights-based TOPSIS model (Technique for Order Preference by Similarity to Ideal Solution), following a multi-criteria decision analysis (MCDA) approach, to quantitatively analyze the most influential measures and indices over the entire life cycle of contaminated site management (from site investigation to land reuse) in China. Results indicate that the sustainability performance of different sites varies widely due to differences in the best management practices (BMPs) implemented. Environmental dimensions in strategy design and remediation implementation processes contribute most to the overall sustainability performance when whole life-cycle management is considered, with social dimensions relatively under-emphasised. Based on a sensitivity analysis of the TOPSIS method, random variations of indices' weights did not result in significant alteration of the modelled sustainability performance of the evaluated sites, which indicates that the method provides a relatively robust approach. The MCDA approach developed enables stakeholders to adopt optimal BMPs for risk control and to enhance sustainability performance in contaminated site management, covering the whole life cycle of site remediation and redevelopment, although further work is required to determine its international applicability.

3D Resistivity Imaging Investigation for Engineering Construction Project Studies at Al-Muthana Airport in Baghdad, Iraq

Engineering project assessment at Al-Muthana Airport in Baghdad, Iraq, has been studied using a 3D electrical resistivity imaging survey. The site investigation is crucial for assessing the future of the region's infrastructures since it reveals the location of buried facilities or weak zones below the surface and measures localized groundwater levels. Wenner-Schlumberger array was used to conduct four parallel 2D electrical resistivity spreads (MU1 to MU4). Each spread line was 100 m in length with 1 m electrode spacing and an average spacing of 9 meters between any two adjacent lines. The depth of the investigation was around 23.8 m. Survey lines were drawn going from northwest to southeast. These spreads were combined to provide a 3D image of a 2700 m2 space.The robust inversion method and the inverse model generated using the standard least-squares method showed horizontal slices identified three zones with resistivity distribution ranging from 2 to 45.5 ohm.m. The first zone, from surface to 3.37 m, had relatively high resistivity of sandy silty clay soil with relatively low moisture content; the second zone, approximately from 3.37 to 12.2 m, had very low resistivity representing groundwater table; and the third zone, from 12.2 to 23.8 m representing high stiffness and density and relatively high resistivity due to gravel presence in the deposits. The second zone highlights potential risk zones for construction projects; as a result, it is advised that the zone surrounding the foundation be filled with a low permeability layer and that the towers be built on deep foundations.

Assessment of canister degradation for the encapsulation of spent nuclear fuel: Key research issues encountered in recent regulatory reviews and government decision making in Sweden

Abstract. Regulatory review of a licence application for construction and operation of a geological repository for radioactive waste should not only be based on information provided by the applicant but also on viewpoints brought up by stakeholders and decision makers. In the Swedish Radiation Safety Authority's (SSM) licensing review of a spent fuel repository at the Forsmark site, the main concerns brought up in court hearings, from national consultations and by the Swedish government were focused around the long-term protective capacity of the copper canisters with cast iron inserts. The most debated canister degradation mechanisms were anoxic corrosion of copper (in oxygen gas free water), localised sulphide corrosion (pitting corrosion and stress corrosion cracking), the influence of gamma radiation, and strain hardening of the canister cast iron insert. The main question addressed by SSM is not whether such effects can be ruled out altogether, but rather their potential extent and influence on canister integrity during a sufficiently long period in the repository environment. Constraints are mainly based on rock properties and associated hydrological and geochemical factors known from site investigation and knowledge about the protective capability of the buffer barrier. The key factors are in general well characterised and cover for instance sulphide availability, groundwater flow, mass transfer rates and expected mechanical loading on canisters in the repository environment. The canister corrosion/degradation mechanisms reviewed in this paper are judged by SSM to have a small or limited importance for demonstration of regulatory compliance, taking into account the characteristics of the site, the function of the buffer, and the margins provided by the significant thickness and mechanical strength of the proposed canister.

Budget Impact Tool for Implementing Contingency Management for Co-occurring Alcohol Use Disorders and Serious Mental Illness.

Contingency management (CM) is a behavioral intervention in which tangible incentives are provided to patients when they achieve a desired behavior (e.g., reducing or abstaining from alcohol use). The authors sought to describe the resource requirements and associated costs of various CM versions (usual, high magnitude, and shaping) tailored to a high-risk population with co-occurring serious mental illness and severe alcohol use disorder. A microcosting analysis was conducted to identify the resource requirements of the different CM versions. This approach included semistructured interviews with site investigators, who also staffed the intervention. The resource costing method-multiplying the number of units of each resource utilized by its respective unit cost-was used to value the resources from a provider's perspective. All cost estimates were calculated in 2021 U.S. dollars. The cost of setting up a CM program was $6,038 per site. Assuming full capacity and 56% of urine samples meeting the requirement for receipt of the CM incentive, the average cost of 16 weeks of usual and shaping CM treatments was $1,119-$1,136 and of high-magnitude CM was $1,848-$1,865 per participant. A customizable tool was created to estimate the costs associated with various levels of treatment success and CM design features. After the trial, the tool will be updated and used to finalize per-participant cost for incorporation into a comprehensive economic evaluation. This costing tool will help a growing number of treatment providers who are interested in implementing CM with budgeting for and sustaining CM in their practices.