Bayesian optimization for CPT-based prediction of impact pile drivability

Pile drivability predictions require information on the pile geometry, impact hammer, and the soil resistance to driving (SRD). Current SRD prediction methods are based on databases of long slender piles from the oil and gas industry and new, robust, and adaptable methods are required to predict SRD for current offshore pile geometries. This paper describes an optimization framework to update uncertain model parameters in existing axial static design methods to calibrate SRD. The approach is demonstrated using a case study from a German offshore wind site. The optimization process is undertaken using a robust Bayesian approach to dynamically update uncertain variables during driving to improve simulations. The existing method is shown to perform well for piles with geometries that reflect the underlying database such that only minimal optimization is required. For larger diameter piles, relative to the prior best estimate, optimized results are shown to provide significant improvements in the mean calculations and associated variance of pile drivability as more data is acquired. The optimized parameters can be used to predict SRD for similar piles in analogous ground conditions. The demonstrated framework is adaptable and can be used to develop site-specific calibrations and advance new SRD methods where large pile driving data sets are available

Optimization of impact pile driving using optical fiber Bragg-grating measurements

This paper reports the use of optical fiber Bragg-grating (FBG) sensors to monitor the stress waves generated below ground during pile driving, combined with measurements using conventional pile driving analyzer (PDA) sensors mounted at the pile head. Fourteen tubular steel piles with a diameter of 508 mm and embedded length-to-diameter ratios of 6∶20 were impact driven at an established chalk test site in Kent, United Kingdom. The pile shafts were instrumented with multiple FBG strain gauges and pile head PDA sensors, which monitored the piles’ responses under each hammer blow. A high-frequency (5 kHz) fiber optic interrogator allowed a previously unseen resolution of the stress wave propagation along the pile. Estimates of the base soil resistances to driving and distributions of shaft shear resistances were found through signal matching that compared the time series of pile head PDA measurements and FBG strains measured below the ground surface. Numerical solutions of the one-dimensional wave equation were optimized by taking account of the data from multiple FBG gauges, leading to significant advantages that have potential for widespread application in cases where high-resolution strain measuremen

Stretching the IR theoretical spectrum on Irish neutrality: a critical social constructivist framework

In a 2006 International Political Science Review article, entitled "Choosing to Go It Alone: Irish Neutrality in Theoretical and Comparative Perspective," Neal G. Jesse argues that Irish neutrality is best understood through a neoliberal rather than a neorealist international relations theory framework. This article posits an alternative "critical social constructivist" framework for understanding Irish neutrality. The first part of the article considers the differences between neoliberalism and social constructivism and argues why critical social constructivism's emphasis on beliefs, identity, and the agency of the public in foreign policy are key factors explaining Irish neutrality today. Using public opinion data, the second part of the article tests whether national identity, independence, ethnocentrism, attitudes to Northern Ireland, and efficacy are factors driving public support for Irish neutrality. The results show that public attitudes to Irish neutrality are structured along the dimensions of independence and identity, indicating empirical support for a critical social constructivist framework of understanding of Irish neutrality

Bayesian optimisation for CPT-based prediction of impact pile driveability

No abstract available

Technology readiness in a B2B online retail context: an examination of antecedents and outcomes

This paper develops and empirically tests a model that examines the role of Technology Readiness (TR) in the Business-to-Business (B2B) context. The research investigates how retailers’ TR, and its antecedents, impacts their evaluation of a credence based B2B service, namely web solution service providers (WSSPs). It responds to previous research calls by extending the TR construct from the business-to-consumer (B2C) perspective that is traditional in the extant literature into the B2B domain. The findings of a survey conducted with 133 firms in the retail industry are that TR is an important contributor to the eventual achievement of service quality and satisfaction. The contributions of this study are; first it develops and validates a measure of TR in a B2B context; second it investigates the antecedents of TR in this domain, demonstrating the impact of past inexperience, industry trust and switching costs on firms’ level of technology readiness to adopt online operations; and third, it finds that service quality and satisfaction are outcomes of TR. The key management implication for WSSPs is the need to address the TR levels of existing and potential clients if they wish to deliver successful e-business solutions to them. Their clients’ TR can be better managed by making the offering more easily understood, building relational rapport, reducing risk perceptions and adopting a client centric perspective throughout the process