Magnetic Induction Technology-Based Wireless Sensor Network for Underground Infrastructure, Monitoring Soil Conditions, and Environmental Observation Applications: Challenges and Future Aspects

Wireless sensor networks (WSNs) especially with sensor nodes communicating with each other in medium other than air have been naive area of research since the last few years. In comparison to underwater communication, wireless underground sensor networks (WUSNs) are now being used in a large number of applications ranging from environmental observation, estimating chances of earthquake, communicating in underground tunnels or mines, and infrastructure monitoring to soil monitoring for agricultural purposes. In spite of all such promising applications, due to harsh and dynamically changing soil characteristics including soil type, water content in soil, and soil temperature, underground communication with conventional electromagnetic (EM) wave-based technology could not prove to be feasible for long-distance communication. Alternatively, due to magnetic permeability of soil being similar to air, magnetic induction- (MI-) based approach was adopted using magnetic coils as antenna for sensor nodes. Subsequently, MI waveguide and 3D coil mechanisms were considered to improve the system efficiency. Attributing to different characteristics of underlying transmission channels, communication protocols as well as architecture of MI-based WUSNS (MI-WUSNs) have been developed with different approaches. In this review paper, in addition to the latest advancements made for MI-WUSNs, closely associated areas of MI-WUSNs have also been explored. Additionally, research areas which are still open to be worked upon have been detailed out.

Parametric Sensitivity Study of Deep Excavation in Singapore Old Alluvium Formation

Deep excavation supported by vertical retaining walls together with strutting system is commonly used in Singapore for the construction of underground infrastructure. In this paper, a series of numerical scenarios simulated by PLAXIS software are carried out to study the influence of different design parameters such as pre-auger loosening effect, the embedded depth of retaining wall into the stiff soil layer, and the elastic modulus of the ground improvement layer on excavation design especially on strut force, retaining wall deflection, and bending moment. The results show that there is high risk if only a single set of parameters are used as input to predict the performance of the retaining system. Sensitivity analysis shall be carried out to evaluate the effects of these parameter variations within a reasonable range on strut force, retaining wall deflection, and bending moment.

A New Methodology for the Detection and Extraction of Hyperbolas in GPR Images

Reliable detection of underground infrastructure is essential for infrastructure modernization works, the implementation of BIM technology, and 3D cadasters. This requires shortening the time of data interpretation and the automation of the stage of selecting the objects. The main factor that influences the quality of radargrams is noise. The paper presents the method of data filtration with use of wavelet analyses and Gabor filtration. The authors were inspired to conduct the research by the fact that the interpretation and analysis of radargrams is time-consuming and by the wish to improve the accuracy of selection of the true objects by inexperienced operators. The authors proposed automated methods for the detection and classification of hyperboles in GPR images, which include the data filtration, detection, and classification of objects. The proposed object classification methodology based on the analytic hierarchy process method introduces a classification coefficient that takes into account the weights of the proposed conditions and weights of the coefficients. The effectiveness and quality of detection and classification of objects in radargrams were assessed. The proposed methods make it possible to shorten the time of the detection of objects. The developed hyperbola classification coefficients show promising results of the detection and classification of objects.

IDENTIFYING DEVELOPMENT PRIORITIES OF UNDERGROUND INFRASTRUCTURE IN METROPOLISES USING SYSTEM METHODOLOGY

Purpose: Determining construction priorities of underground transport infrastructure objects by evaluating morphological models of car tunnels considering the impact on the ecological and technogenic safety of urbanized territories. Methodology: modified morphological analysis of geological environment, urbanized territories and transport infrastructure of sites in a metropolis, expert estimation method. Findings: a morphological model was tested as a tool set for determining construction priorities of underground transport infrastructure objects; inter-related morphological tables for geological environment and structural-functional factors of urbanized territories in a tunnel area were constructed; an estimation of models regarding development of underground infrastructure was conducted using the planned car tunnels in Kyiv as an example; the impact of tunnels on reducing the ecological and technogenic risks of urbanized space was justified, and the priority construction object was chosen according to these criteria. Originality: for the first time the reduction of ecological and technogenic risks of urbanized space was chosen as a goal function in morphological models for the development of underground transport infrastructure in metropolises; the systemic characteristics of urban territories were obtained that describe the favorability of the geological environment and structural-functional factors for car tunnel construction in center metropolis areas; an impact ratio was proposed for synthesizing morphological analysis results and determining the priorities of underground transport infrastructure objects by influence on the ecological and technogenic risks. Practical implications: the created methodology and tool set for determining priorities of underground object construction at the pre-project stage, the opportunity to consider the ecological and technogenic risks of urban space development by consecutive construction of underground transport infrastructure objects and identifying an order for this sequence.

Living with Urban Flooding: A Continuous Learning Process for Local Municipalities and Lessons Learnt from the 2021 Events in Germany

In 2021, heavy precipitation events in Germany have confirmed once again that pluvial flooding can cause catastrophic damage in large, medium, and small cities. However, despite several hazard-oriented strategies already in place, to date there is still a lack of integrated approaches to actually preventing negative consequences induced by heavy rainfall events. Furthermore, municipalities across the world are still learning from recent episodes and there is a general need to explore new techniques and guidelines that could help to reduce vulnerability, and enhance the resilience, adaptive capacity, and sustainability of urban environments, considering the already predicted future challenges associated with climate variability. To address this gap, this paper presents the outcomes of the research project “Heavy Rainfall Checklist for Sewer Operation” which was conducted by IKT Institute for Underground Infrastructure, to involve all the stakeholders affected by pluvial flooding within cities, and implement a series of documents that can be adopted by municipalities across the world to support organizations and their operational staff in preventing problems caused by heavy rainfall incidents. More in detail, three different rainfall scenarios have been deeply analysed, and for each of them a list of specific tasks and suggestions has been provided for aiding decision-making.

Dependence of Underground Infrastructure and Land Management in Urbanized Areas

The article presents a current view on the issue of supplying utilities to land regarded differently than merely technical solutions. The authors offer an insight to the issue of the technical supplying of urbanized areas, treating such infrastructure as a determinant of the coexistence of buildings and transfigurations of the urban fabric. Using selected examples of novel means of identifying existing solutions of the underground technical infrastructure (canals, sewage and stormwater networks, transportation and communication tunnels, building in additional contemporary of installations of logical networks or unidentified remains of past development), the need to carry out additional analyses and prepare a new, or update-change the existing local spatial development plan were identified. It was noted that The construction of underground infrastructure corridors ought to be the key, preceding the issuing of building permits, the commencement of activities by developers as well as administrative conditions. The underground infrastructure has an influence of the dynamics as well as quality of spatial transformations of urbanized areas.

Testing, Analysis and Classification of No-Dig Manhole Rehabilitation Materials

Gravity flow wastewater collection systems are comprised of sewer pipes and manholes. Failure of a manhole may have catastrophic consequences such as developing a sinkhole in the street and roadway, and at a minimum, wastewater flow will be blocked, and stream of the manhole will backup causing a sanitary sewer overflow (SSO). Improving structural conditions of a manhole is critical to minimize these types of failures. This paper considers the impact of several lining materials including cement mortar, epoxy, polyurethane, cured-in-place composites, and a multi-layer structure material on increasing the structural capabilities of deteriorated manholes. The tasks included in this research consist literature search and, preliminary laboratory and main testing of select manhole rehabilitation materials. A finite element analysis is included to complement the experiments. Several preliminary tests according to ASTM C-39 on coated concrete cylinders, and ASTM C-293 on lined concrete beams, were performed at UT Arlington's Center for Underground Infrastructure Research and Education (CUIRE) Laboratory. The test results showed significant increase in the performance of concrete samples under compression and flexure. A second round of testing was performed on 4-ft long, 24-in. diameter concrete pipe sections with 3-in. wall thickness manufactured according to ASTM C-76. These pipe sections were lined internally with the same materials as the preliminary tests, and tested according to ASTM C-497 under Three-Edge-Bearing testing. Using computer data acquisition system, strain gages and displacement extensometers, stress/strain data were measured. The results showed that tested No-Dig manhole rehabilitation materials can significantly improve structural performance of deteriorated manholes.