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2023 | Buch

Geotechnical Instrumentation and Applications

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Geotechnical Instrumentation and Applications explains the geotechnical issues encountered in the implementation of construction projects dealing with ground, groundwater, and earth infrastructures, including land reclamations, dams, embankments, landfill construction, excavations, and tunnelling. The book describes the types of geotechnical instrumentation available in the market and walks readers through the geotechnical issues usually encountered in construction projects and observational methods applying geotechnical instruments, planning, and implementation of geotechnical instrumentation projects. Detailed coverage of the calibration and installation process of geotechnical instruments, the verification of measured data, and the recording and documentation of as-built drawings of geotechnical instruments installed are presented. Coverage also includes methods of measurement, recommended monitoring frequencies for manual monitoring and methods of data processing and presentation, as well as analyses and interpretations of monitored data for performance assessment. Factors affecting measured instrument data are also discussed with a few examples. Case studies are presented with field data collected during the implementation of large-scale ground improvements and ground engineering projects involving extensive geotechnical instrumentation works. The book will be an ideal text for upper-undergraduate and graduate geotechnical engineering, foundation engineering, and soil mechanics courses and a hands-on reference for practitioners who apply geotechnical instrumentation in the construction industry.

Inhaltsverzeichnis

Frontmatter
Chapter 1. Introduction
Abstract
Dealing with the earth involves substantial uncertainty. Uncertainties range from inherit variations of ground and groundwater profile, their strength, compressibility and hydraulic characteristics and their responses to additional stresses imposed on them. In addition to their variation of profile, their strength, stiffness and compressibilities and hydraulic characteristics vary across the area as well as along the depth they existed. To make the situation worse, their ability to absorb water and capacity to flow through porous media within them are also varied. Moreover, when additional stresses are imposed on the soils and rocks, the magnitudes, rates, and directions of stresses are varied. Stresses transferred onto the soils and ground/pore water could also be varied depending upon the behaviour of soil structure interaction which also varies depending upon the type of soil. To make things worse, changes in environmental conditions such as change in surface and ground water levels/pressures, temperature also could lead to change in the performance of soils and rocks under additional stresses. These changes impact performance of the ground and groundwater/porewater contained in the ground. Significant variations beyond the tolerable deformation could lead to failure of infrastructure built on the ground.
Myint Win Bo, Jeffrey Barrett
Chapter 2. Observational Methods and Geotechnical Issues
Abstract
This chapter explains and discusses about observational methods and geotechnical issues usually encountered in the construction projects. The kinds of problem encountered are discussed under a few categories of changes such as settlement, slope instability and lateral displacements, change in groundwater and porewater pressures, induced vibration and structural deformations. Depending upon the types of construction works and potential issues likely to encountered, a suitable type of instrument to be installed at recommended best locations and arrangement are discussed to measure the required parameters. Advantages of using and implementing geotechnical instrumentation programme and observational methods are also discussed in this chapter.
Myint Win Bo, Jeffrey Barrett
Chapter 3. Types of Instruments
Abstract
There are several types of geotechnical instruments. Some measure deformation, and other measure pressure and stress. In order to manage the geotechnical issues likely to encounter during and after construction, two basic categories of geotechnical instrumentation programmes are usually implemented.
Category A
Measurement of Ground behaviour during construction in order to control the construction process.
Category B
Monitoring of performance of ground during loading, unloading and soil improvement process.
By measuring deformations and stresses, progress leading to failure or progress of improvement can be detected. With systematic planning of monitoring frequencies, infrastructure can be built safely without failure by applying the observational method using data from geotechnical instruments installed in accordance with Category A. On the other hand, degree of soil improvement can be verified using monitoring data collected through geotechnical instrument installed in accordance with Category B. In both cases, any rectification required due to unforeseen or unexpected performances can be implemented when the monitoring data collected and interpreted results indicate as an alert. This chapter will walk through several types of geotechnical instrument available in the market to measure respective deformations, strains, stresses and pressures within/underneath and on the earth masses and structural elements.
Myint Win Bo, Jeffrey Barrett
Chapter 4. Planning Geotechnical Instrumentation Project
Abstract
Geotechnical instruments and their monitoring results are used in all stages such as prior to construction, during construction and after construction. Geotechnical instruments used prior to construction are kinds of measurement required to understand the site conditions and data required for design process. Some instruments are also installed to collect baseline information. These could be used as legal information in any dispute on change in unwanted conditions due to construction activities.
In planning for geotechnical instrumentation projects, the first step to consider is: there must be a justification why geotechnical instrument should be installed. In general, geotechnical instruments are installed to solve the problem or to put the potential problem under control except for those instruments installed to obtain design parameters or to obtain baseline information. Planning of geotechnical instrumentation projects normally develops step by step as shown below:
  • Determining issues to be solved
  • Determining kinds of measurement required
  • Setting objective of measurements
  • Selecting types of instruments to monitor and collect required measurements
  • Selecting instrument with a suitable method of measurement (e.g. pneumatic, hydraulic or vibrating wire)
  • Selecting suitable range and accuracy of measurement
  • Determining locations to be installed
  • Determining depths/levels to install
  • Determining total numbers of instruments required for each type of instrument
  • Preparing monitoring frequency
  • Preparing remedial plan
  • Preparing specification
  • Estimating budget
  • Deciding procurement process
  • Preparing contract and agreement
Table 4.1 shows kinds of instrument installed prior to construction which can be used as baseline information.
Myint Win Bo, Jeffrey Barrett
Chapter 5. Geotechnical Instrument Installation
Abstract
Geotechnical instruments are installed at the planned locations, depths and places depending upon the types of instrument. Some instruments are installed on the surface and/or on the existing ground levels, whereas some are installed in the boreholes in order to monitor the behaviour of soil elements at particular depths for specific types of soil. Others are installed on the structural elements such as foundations, retaining walls and support element such as piles, anchors and struts.
Myint Win Bo, Jeffrey Barrett
Chapter 6. Monitoring, Data Processing, Data Verification and Presentation
Abstract
After installation of the instrument, it is necessary that collected monitoring data are verified to ensure that the instruments and data acquisition systems are operating properly. In many cases, verifications can be carried out based on initially collected zero reading after stabilization. However, some instruments required significant poll of data to verify the accuracy and precision of monitored data. These details together with monitoring frequency, monitoring process, data processing, data verification and presentation of monitored data are presented in this chapter. Automatic real-time monitoring system and recent development of data acquisition systems and visualization software are also discussed in this chapter.
Myint Win Bo, Jeffrey Barrett
Chapter 7. Analyses and Performance Assessment
Abstract
Monitored data using geotechnical instrument are required to be analysed to obtain the necessary indications of achievement, target/trigger or alert warnings, etc. Using these outputs from analyses, appropriate decisions related to remedial actions or acceptances could be made.
Measurements of achievement, definitions of alert and target/trigger levels are different for each instrument. These will be explained in more details for the following types of issues in the following sections of this chapter.
  • Settlement and consolidation
  • Lateral displacement and slope stability
  • Earth pressure
Myint Win Bo, Jeffrey Barrett
Chapter 8. Factors Affecting Measured Instrument Data
Abstract
Accuracy, precision and reliability of monitoring data of geotechnical instrument depend on methods of installation and measurements, functionality and performance of installed instrument. This chapter will explain some details on methods of installation, measurement, functionality and performance of instrument which can affect the measured monitoring data.
Myint Win Bo, Jeffrey Barrett
Chapter 9. Case Studies
Abstract
This chapter presents application of geotechnical instrumentation and observation methods in the construction projects during the last few decades. Geotechnical instrument to monitor change in ground and groundwater conditions and pressures, stresses, deformations etc., is monitored during the construction of the infrastructures. In the following sections, case studies written by engineers who were intensively involved in the implementation of such projects especially in geotechnical and geotechnical instrumentation aspects of the works are presented. Geotechnical instrumentation has been utilized in the following construction projects:
1.
Land reclamation
 
2.
Ground Improvement
 
3.
Landfill
 
4.
Dam and embankment
 
5.
Highway, railway and bridge
 
6.
Excavation
 
7.
Tunnelling
 
8.
Deep foundation, but not limited to
 
In this chapter, a few selected case studies on application of geotechnical instrumentation in land reclamation and ground improvement project, slope stability project, excavation project and tunnelling project are presented.
Myint Win Bo, Jeffrey Barrett
Backmatter
Metadaten
Titel
Geotechnical Instrumentation and Applications
verfasst von
Myint Win Bo
Jeffrey Barrett
Copyright-Jahr
2023
Electronic ISBN
978-3-031-34275-2
Print ISBN
978-3-031-34274-5
DOI
https://doi.org/10.1007/978-3-031-34275-2