The Use of Geophysical Methods in Identifying Tree Roots in Urban Areas

Currently, the spread of megalopolises poses an ever-increasing necessity for underground space development for the purpose of the arrangement of transport communications, underground parking areas, trade areas, etc. The implementation of such projects entails a significant increase in the risk of accidents and damage to existing buildings within construction activity influence areas. The reduction of the risk of accidents during the construction of underground facilities within urban areas may only become possible with the identification of adverse factors negatively influencing existing buildings or a facility under erection and elaboration (to reduce such negative influence). The application of geophysical methods in complex assessments of the actual state of an encompassing mass significantly increases efficiency and the credibility of geotechnical monitoring. The application of seismic tomography significantly increases the resolution capability of surveys. Existing techniques, e.g., seismic tomography, allow for any depths to be investigated at a high resolution, even given constricted urban conditions. This article covers the practical applications of seismic tomography in qualitative assessments of actions and an efficiency evaluation of the injective stabilization of soil.

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The Management of Tree Root Systems in Urban and Suburban Settings II: A Review of Strategies to Mitigate Human Impacts

Arboriculture & Urban Forestry ◽

10.48044/jauf.2014.025 ◽

2014 ◽

Vol 40 (5) ◽

Author(s):

Gary Watson ◽

Angela Hewitt ◽

Melissa Custic ◽

Marvin Lo

Keyword(s):

Urban Areas ◽

Human Impacts ◽

Natural Infection ◽

Root Systems ◽

Sewer Pipe ◽

Root Space ◽

Tree Roots ◽

Tree Health ◽

Urban Tree ◽

Decay Development

Root systems of nearly all trees in the built environment are subject to impacts of human activities that can affect tree health and reduce longevity. These influences are present from early stages of nursery development and throughout the life of the tree. Reduced root systems from root loss or constriction can reduce stability and increase stress. Natural infection of urban tree roots after severing has not been shown to lead to extensive decay development. Roots often conflict with infrastructure in urban areas because of proximity. Strategies to provide root space under pavements and to reduce pavement heaving have been developed, but strategies for prevention of foundation and sewer pipe damage are limited to increasing separation or improved construction.

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Detection of Underground Anomalies Using Analysis of Ground Penetrating Radar Attribute

Inżynieria Mineralna ◽

10.29227/im-2020-01-04 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Cuong Van Anh LE ◽

Thuan Van NGUYEN

Keyword(s):

Ground Penetrating Radar ◽

Urban Areas ◽

Geophysical Methods ◽

Synthetic Data ◽

Drainage System ◽

Real Data ◽

Building Structures ◽

Water Drainage ◽

Diffraction Curve ◽

Ground Penetrating

Need of specifying underground construction works for supporting further tasks as maintenance, repairing, or setting up new underground structures. For these needs, ground penetrating radar, one of the efficient geophysical methods, can bring high-resolution and quick underground image revealing existence of both natural and artificial anomalies. Its fixed receiver-transmitter antennas setting as constant offset is commonly used in urban areas. Conventionally, hyperbolae events are crucial indicator for scattering objects as kinds of pipes, water drainage system, and concrete building structures as well as sink holes. Calculation of their depths and sizes requires migration analysis with the environment velocity. Migrated sections with different velocity show different chaos degrees of transformation from a hyperbola diffraction curve to its focused area. We have researched diagrams of different Ground Penetrating Radar attributes as energy, entropy, and varimax dependent on two variables, velocity and window zone covering diffraction events from a set of synthetic data and real data, in specifying the environment velocity. We have developed a novel technique for evaluation of the ground velocity and object’s size by combination of the new varimax diagram and the Kirchhoff migration method. The technique can define contribution of diffracted ground penetrating radar waves for building the diagram after removing the reflection contribution. The synthetic datasets consist of different random background noise levels and expressions of different-sized circular and rectangular pipes. The real data is measured for detecting two underground gas pipes in Ba Ria – Vung Tau province, Vietnam.

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Geophysical prospecting in the Doukkala area (Swalah commune) in Morocco

E3S Web of Conferences ◽

10.1051/e3sconf/202015003008 ◽

2020 ◽

Vol 150 ◽

pp. 03008

Author(s):

Halima Soussi ◽

Lahcen Bahi ◽

Latifa Ouadif ◽

Mohamed Chibout ◽

Brahim Aghazzaf ◽

...

Keyword(s):

Rural Areas ◽

Urban Areas ◽

Geophysical Methods ◽

Economic Consequences ◽

Vertical Electrical Soundings ◽

Damage Costs ◽

Electrical Soundings ◽

Urban And Rural Areas ◽

El Jadida ◽

Very High

The collapse of the subsoil creates a risk for the population whether it is urban or rural. Each year, the damage caused by these collapses has considerable socio-economic consequences, and the damage costs are very high. Thus, the detection of these areas of collapse in urban and rural areas is important to prevent and avoid socio-economic consequences, and to establish a preventive risk planning to have a better protection of people and goods. The commune of Swalah, study area, belongs to the province of El Jadida which is part of those areas of Doukkala exposed to the risk of collapse due to the presence of underground cavities. These cavities are potentially dangerous for humans, especially in urban areas. They have different extensions that can be caused by natural or anthropic origin. Their size, as well as the physical properties of the external environment in which they are located, allow the use of different geophysical methods. The use of these geophysical methods is the best to detect and delineate cavities in this region. The present study was based on a geophysical compaign of vertical electrical soundings. Indeed, 50 electrical soundings were modeled and reinterpreted and allowed to detect and delineate any potential cavities in the region.

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Evaluating the Geotechnical and Geophysical Characteristics of Expanding Districts in Tehran Using Field Experiments

Civil Engineering Journal ◽

10.28991/cej-030997 ◽

2018 ◽

Vol 4 (2) ◽

pp. 363

Author(s):

Arash Razmyar ◽

Abolfazl Eslami

Keyword(s):

Urban Areas ◽

Field Experiments ◽

Geophysical Methods ◽

Field Tests ◽

Young Modulus ◽

Friction Angle ◽

Standard Penetration Test ◽

Penetration Test ◽

Engineering Structures ◽

Geotechnical Characteristics

Considering the increasing population growth and the rapid growth of urbanization and pollution in the environment, providing zoning maps and urban engineering geology seem to be important. The rapid construction growth of cities, as well as the confrontation with events such as earthquakes and failure to observe the geological and geotechnical issues, has caused many engineering problems. The use of geophysical methods not only cannot lonely provide us a complete and comprehensive information on the geotechnical conditions of the earth but also has many disturbances in urban areas, and its use in urban centers is almost impractical. Therefore, it seems that the best way of examining and interpreting the geotechnical characteristics of a site, especially in urban areas, is the use of suspicious data. Therefore, performing geotechnical studies and geotechnical zoning can be useful for retrofitting buildings and engineering structures and reducing their risks. Hence, zoning studies are conducted in this research in order to better recognize the technical soil status for safe construction due to rising the population of Tehran in recent decades and the concentration of population in certain areas of Tehran, especially in the eastern and western regions (districts 4 and 22). In this study, different geotechnical field tests such as standard penetration test (SPT), cone penetration test (CPT) were used to estimate parameters such as adhesion coefficient (C), internal friction angle ( ), Young modulus (E). Other common experiments with conventional geophysical experiments, such as in good experiments, refractive and CSSW were applied to estimate geophysical parameters of bedrock depth and shear wave velocity for zoning these areas.

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Assessment of Root Plate Structure in Wind-Thrown Trees of Melia dubia

Journal of Tropical Forestry and Environment ◽

10.31357/jtfe.v8i1.3482 ◽

2018 ◽

Vol 8 (1) ◽

Author(s):

A. N. Arunkumar ◽

Shakti Chauhan

Keyword(s):

Urban Areas ◽

Primary Root ◽

Base Line ◽

Underground Part ◽

Tree Roots ◽

Large Variability ◽

Strong Positive Relationship ◽

Melia Dubia ◽

Root Plate ◽

Plate Width

Root plays a significant role in tree growth and development and information pertaining to spread of the root and its depth will be useful for establishing plantations. Most of the root studies are generally carried out in trees growing in urban areas in avenues, but limited studies are carried out in plantations. Being an underground part of the tree, there are inherent difficulties in understanding root architecture. Uprooting of trees due to storm or wind damage provides an ideal opportunity to obtain critical understanding about tree roots. Such study has been carried out in an 11 year old storm ravaged Melia dubia plantation in Punjab, India. Field observations such as tree girth, root girth, root plate width and depth was recorded on uprooted trees. A large variability was recorded for all the traits. Root plate width and depth ranged from 1.42 to 5.17 m and 0.75 to 2.50 m, respectively. A strong positive relationship between tree girth and primary root girth, root plate width and depth identified in this study provides base line information which can be used while establishing M. dubia plantations.Keywords: Melia dubia, root plate, root width, root depth, wind-thrown

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2D INVERSION OF DIPOLE-DIPOLE AXIAL ARRAY WITH LINEAR CAPACITIVE ELECTRODES FOR ENGINEERING TASKS

Engineering survey ◽

10.25296/1997-8650-2019-13-2-60-68 ◽

2019 ◽

Vol 13 (2) ◽

pp. 60-68

Author(s):

A. Yu. Tatarskiy ◽

A. F. Volynin

Keyword(s):

Urban Areas ◽

Geophysical Methods ◽

Electrode Array ◽

Field Work ◽

Geological Structure ◽

Industrial Facilities ◽

Data Inversion ◽

2D Data ◽

High Level ◽

2D Resistivity

Abstract: at present, the range of tasks solved by geophysical methods is expanding. This is facilitated by the progress in the development of geophysical equipment, methods for performing field work and data processing. At the same time, the conditions of research are complicated. Often it is the site of industrial facilities or urban areas. The main factors complicating the implementation of the geophysical researches at urban areas are the high level of industrial noise and solid coverage. The article discusses the possibility of using resistance technology with 2D data inversion when solving engineering problems in urban areas. The conditions of the use of the measurement technique with capacitive electrodes for approximation by grounded electrode array at a direct current are shown. The results of the comparison of the dipole-dipole method with capacitive electrode array and its equivalent with galvanic grounded electrodes are presented. To assess the effectiveness of using of the capacitive electrodes array for solving engineering tasks in the city, the authors carried out researches on a site of regularly emerging subsidence of pavement in the center of St. Petersburg. According to the research results, a 2D resistivity section of the pavement deformation was constructed. The results were interpreted using geological information. The studies revealed a spatial correlation of the identified anomalies of specific electrical resistances with the local site of the embankment pavement destruction. The possible causes of the identified anomalies are described. The results of electrical prospecting with linear capacitive electrodes can be used for detailing engineering geological structure of urbanized areas.

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USING SEISMOACOUSTIC METHODS IN KARST TERRITORIES OF LARGE CITIES (A CASE STUDY OF MOSCOW AND NIZHNY NOVGOROD)

Engineering survey ◽

10.25296/1997-8650-2018-12-9-10-50-62 ◽

2019 ◽

Vol 12 (9-10) ◽

pp. 50-62

Author(s):

A. D. Kochev ◽

L. G. Chertkov

Keyword(s):

Urban Areas ◽

Survey Methods ◽

Geophysical Methods ◽

Seismic Survey ◽

Low Velocity ◽

Borehole Geophysics ◽

Large Cities ◽

Common Depth Point ◽

Coal Deposits ◽

Seismic Vibrations

Various geophysical methods are used to study the karst of carbonate massifs, the effectiveness of which in the conditions of large cities is low, since they are affected by intense industrial and transport disturbances. The paper discusses the use of seismic acoustic methods of ground and borehole geophysics: the method of the common depth point (CDP), the method of refracted waves (MRW), crosswell seismoacoustic sounding (CSS). It is shown that seismic survey methods provide more informative engineering-geological research. The use of a non-explosive source of excitation of seismic vibrations made it possible to carry out research in urban areas. As a result of the implementation of a system for accumulating useful seismic signals, informative material was obtained in areas of intense industrial interference. The resolution of seismic surveys on the mapping of coal deposits and the construction of maps of the paleorelief is clearly visible from a comparison of geological maps constructed from drilling data and taking seismic studies into account. In combination with crosshole seismic acoustic sounding, it is possible to fix relatively large karst cavities and destroyed zones. Complicating in the interpretation of seismoacoustic indicators is the fact that the carbonate massif is often a relatively evenly karsted system in the form of karst cavities of various sizes (mostly irregular in shape, filled or open), fracturing, cavernosity and porosity. As a result, the motley pattern of the distribution of the velocities of elastic waves is averaged, making it difficult to isolate low-velocity zones confined to karst cavities. Additionally, according to the data of microseismic logging — vertical seismic profiling (MSL — VSP), it is possible to identify low-speed zones associated with decompaction in the upper cover layer of rocks, from which sandy sediments are transported to a carbonate strongly karsted massif. Seismoacoustic sounding allows you to control the quality of grouting works when filling karst cavities with cement mortar.

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