Barry Clarke

Increasing the Resistance of Piles Subject to Cyclic Lateral Loading

Small-scale tests were carried out on a monopile and fin piles to determine the effect the length of fins had upon the lateral displacement of cyclically loaded piles. A variety of loading conditions were applied to model piles in a dense sand by using a mechanical loading system. Ten thousand cycles were used in each test to represent 20 years of environmental loading on offshore structures. Variables included the magnitude, frequency, and direction of the load; the type of pile tip; and the length of the fins. The reduction in pile head displacement was used as a measure of the efficiency of the fins. The tests show that the fins reduced the lateral displacement by at least 50% after 10,000 cycles.

A Device to Cyclic Lateral Loaded Model Piles

Model tests on small scale piles subject to cyclic lateral loading have been carried out with the purpose of simulating the pile soil behavior and its lateral resistance under environmental loads. An efficient mechanical loading system has been developed. This system is able to provide both one-way and two-way cyclic lateral loads. Frequencies and load levels in both directions can be varied in order to simulate different load conditions. There is no limitation on the number of cycles. A series of lateral cyclic loading tests for a monopile in dry sand have been carried out to demonstrate the efficiency and effectiveness of this loading system. The benefits of this innovative loading system are presented.

The 2011 James Forrest Lecture – engineering education – a historical perspective of the future

The decision in 1747 to create the Ecole Pont et Chausses in Paris to educate engineers has had a significant effect on higher education. The original programme was founded on underlying mathematical principles of calculus, geometry and algebra which, through practice, led to creative solutions. Through innovation driven by scientific discoveries and societal demands, the programmes have evolved into research-led, industry-informed learning experiences. It is this practice of creating a corpus of knowledge and then going on to challenge that knowledge that leads to the contribution that engineers make to society. Recognising and understanding the balance between tradition and innovation is a key feature of engineering degree programmes that equip graduates with a habit of mind that enables them to deal with future challenges. This strengthens the need for research-led teaching that is industry-informed. Achieving that balance has always been difficult but its success is demonstrated by the built environment in which we live, which has been, in part, created by civil engineering graduates. This paper, the written version of the Institution of Civil Engineers 2011 James Forrest Lecture, traces the development of this philosophy, how the consequences have benefited society and how it will develop.

A Flat Dilatometer to Operate in Glacial Tills

The Marchetti flat dilatometer is a simple to operate in-situ testing device that was designed for use in clays, silts, and sands. A new dilatometer has been developed for use in a greater variety of soil types, in particular glacial tills. This probe is more robust than the Marchetti dilatometer because it uses a rigid piston instead of a flexible membrane to load the soil. The new dilatometer is also a research dilatometer incorporating a displacement transducer and pressure transducer. This allows an applied pressure displacement curve to be produced. Tests have been carried out at several sites to compare results from the two dilatometers, check the robustness of the new dilatometer, and produce data to establish new correlations.

Constant Rate of Strain Consolidation Equipment and Procedure for Stabilized Soils

Stiffness, that is, the relationship between applied stress and resulting strain, is a function of applied stress and, in the case of stabilized soils, age. For that reason the standard odometer test may be unsuitable as it can take several days to complete a test and in that time the stiffness will change regardless of stress changes. The constant rate of strain consolidation (CRS) test may be the preferred test to assess the stiffness of stabilized soils. A simple CRS cell has been developed to operate with a standard triaxial loading frame. Comparisons between the results of oedometer tests and CRS tests show that the test procedure and equipment is valid. Tests on stabilized soils show the importance of minimizing the time of a test since there is an increase in stiffness with age.

An Ontology of Soil Properties and Processes

Assessing the Underworld (ATU) is a large interdisciplinary UK research project, which addresses challenges in integrated inter-asset maintenance. As assets on the surface of the ground (e.g. roads or pavements) and those buried under it (e.g. pipes and cables) are supported by the ground, the properties and processes of soil affect the performance of these assets to a significant degree. In order to make integrated decisions, it is necessary to combine the knowledge and expertise in multiple areas, such as roads, soil, buried assets, sensing, etc. This requires an underpinning knowledge model, in the form of an ontology. Within this context, we present a new ontology for describing soil properties (e.g. soil strength) and processes (e.g. soil compaction), as well as how they affect each other. This ontology can be used to express how the ground affects and is affected by assets buried under the ground or on the ground surface. The ontology is written in OWL 2 and openly available from the University of Leeds data repository: http://doi.org/10.5518/54.

Automated Reasoning for City Infrastructure Maintenance Decision Support

We present an interactive decision support system for assisting city infrastructure inter-asset management. It combines real-time site specific data retrieval, a knowledge base co-created with domain experts and an inference engine capable of predicting potential consequences and risks resulting from the available data and knowledge. The system can give explanations of each consequence, cope with incomplete and uncertain data by making assumptions about what might be the worst case scenario, and making suggestions for further investigation. This demo presents multiple real-world scenarios, and demonstrates how modifying assumptions (parameter values) can lead to different consequences.

ATU-DSS: Knowledge-Driven Data Integration and Reasoning for Sustainable Subsurface Inter-Asset Management

Urban infrastructure assets perform critical functions to the health and well-being of the society. In this paper, we present a prototype decision support system for sustainable subsurface inter-asset management. To the best of the authors’ knowledge, this work is the first on assessing the underground space by considering the inter-asset dependencies using semantic technologies. Based on a family of interlinked city infrastructure asset ontologies describing the ground, roads and buried utilities (e.g. water pipes), various datasets are integrated and logical rules are developed to describe the intra-asset and inter-asset relationships. An inference engine is employed to exploit the knowledge and data for assessing the potential impact of an event. This system can be beneficial to a wide range of stakeholders (e.g. utility incident managers) for quickly gathering of the localised contextual data and identifying potential consequences from what may appear as an insignificant trigger. A video demonstrating the prototype is available at: http://bit.ly/2mdyIY4.

Response to discussions by J.P. Mahoney and C.B. Brown

The discussion on the development of civil engineering education in North America and the impact that the economic, environmental and social landscapes had upon the ongoing evolution is very welcome and reinforces the fact that lessons can be learnt from history to ensure that we understand the reasons for the structure and outcomes of the engineering programmes today. This will help in the emerging use of digital learning to ensure that graduates still retain that habit of mind that enables problems to be solved when solutions are not obvious and provide a leadership role in society as engineers face the many challenges of tomorrow with an ability to deal with transformational change. Learning will have to become more personalised; knowledge sources will be more diverse; academics will become ‘guides on the side’ rather than ‘sages on the stage’; and the role of engineers as mentors will expand. Prof. Brown and Prof. Mahoney have captured this in their discussion highlighting the need to learn from history in developing the educational base for the twenty-first century engineer.

Surface Coal Mining and the Reclamation of Tips, Landfills and Quarries – Some Geotechnical Case Studies from Northern England

Underground coal mining has almost disappeared from Northern England as the deeper terrestrial reserves have been exhausted, and only one mine still continues to extract undersea coal. The legacy of this once major industry has been the creation of many tracts of derelict land and abandoned colliery tips. Old tips are associated with potential hazards such as instability, combustion and contamination, and they are often considered to be visually intrusive or an obstruction to re-development. Surface coal mining is also in decline, due to increased public perception that it causes environmental nuisance and damage, which has resulted in the introduction of ever more restrictive planning statutes, even though it provides a cost effective way of restoring old tips and derelict land. A consequence of this has been the identification of a wider relationship between land reclamation works and the extractive industries which includes underground mining and tips, surface mining and quarrying, and landfilling and contaminated land. The design of surface mining projects to incorporate restoration of tips and derelict land often poses difficult geotechnical and geo-environmental engineering problems. Several case studies illustrate how some of these problems have been resolved for specific restoration projects.