Deformation and damage to buildings caused by ground movements in mining areas (case study) (original) (raw)
Related papers
Journal of Measurements in Engineering
Mining tremors belong to so-called paraseismic sources of vibrations and can be classified as the most intensive of such type sources of surface structures vibrations, hazardous for buildings. According to the soil-structure interaction effect, the ground vibrations are modified during their transmission to foundations of building. In consequence, the differences between the records of vibrations registered on the ground next to a building and at the building foundation (simultaneously), can be significant. The paper is focused on the analysis of the differences in the approximate assessments of the harmfulness of mine-induced rockbursts on the basis of simultaneously occurring free-field vibrations next to the building, or building foundation vibrations. The analysed vibrations were induced by shocks in the Upper Silesian Coalfield (USC), one of the most seismically active area in Poland. Typical administrative, masonry, low-rise actual building was taken into account. The harmfulness of mining-induced vibrations to the building was estimated using appropriately prepared scales for this region. Results corresponding to two versions of the scales were analysed: the new proposition-Mining Seismic Intensity Scale GSIS-2017, as well as its former version-the Mining Intensity Scale GSI-GZW KW-2012. Both of the scales were considered in two versions: velocity version (basic), and acceleration version (auxiliary). It is worth mention that these scales base on the ground vibration parameters. However, for research and comparison purposes, they were applied also for building foundation vibrations.
Dynamic investigations of various civil engineering structures due to ambient and mining tremors
The first part of the study deals with evaluation of dynamic characteristics of selected typical industrial facilities, such as the extraction steel tower, reinforced concrete tower skips. These structures are located in the coal mine area. The constructions of the test items are varied and complicated, which causes difficulties in the research in situ. In the investigation we used normal and emergency operation of lifting equipment, the effect of wind gusts and rhythmic man swaying. The second part of the study involves the determination of the dynamic characteristics of tailing dam. In this case mining tremors were used as the sources of vibration excitations. By using natural vibration excitation source it was possible to determine the lowest frequency of free vibration of the tailing dam. The third part of the paper focuses on the results of measurements of mine-induced ground vibrations and vibrations of residential buildings of various types. Typical one-family masonry houses as well as 5 and 12 storey reinforced prefabricated buildings were examined. The studies were conducted to determine the transmission of free-field vibrations to the building foundations. According to the significant differences between the simultaneously measured ground and building foundation vibrations, results of experimental tests obtained by means of response spectra are essential for the proper adoption of kinematic loads for dynamic models of these structures. The results of experimental studies were the basis for the verification of dynamic models of investigated structures.
The Impact of High-Energy Mining-Induced Tremor in a Fault Zone on Damage to Buildings
Energies
Seismic energy propagation from the hypocentre of mining-induced tremors usually causes an uneven distribution of the peak ground velocity PGVHmax in tectonically complicated structures, and consequently, an uneven distribution of damage to buildings located on the ground surface. This study aimed to estimate the impact of high-energy mining-induced tremors in fault zones on damage to buildings. In the study, we describe a case of one of the highest-energy mining-induced tremors E = 4.0 · 108 J (local magnitude ML = 3.6) that occurred in the Upper Silesian Coal Basin (USCB), Poland. The hypocentre of the tremor was most probably located in the Barbara fault zone, one of the larger faults in that western part of the USCB. Numerous damaged buildings on the terrain surface were registered, both in the epicentral zone and at a greater distance from the epicentre, mostly from the southern side of the Barbara fault zone. We calculated that the tremor was characterised by a normal slip mec...
Czasopismo Techniczne. Budownictwo, 2016
Sometimes, deep mining introduces particular seismic risk to buildings on the surface; therefore, special procedures are needed to assess the safety limits of ground motion. This paper demonstrates such a procedure for use when the standard approach fails to properly asses intensity. Peak velocity is chosen to measure seismic intensity. Forecasted and past seismicity is compared with structural damage assessments to make a decision allowing safe mining in a given location.
Proceedings of the 6th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015), 2017
The study analyses the results of measurements of mining related surface vibrations in the Legnica-Glogow Copper Region (LGCR) to assess the impact of mining tremor epicentral distances as well as mining tremors energies on a curve relationship (ratio) of response spectra (RRS) from simultaneously measured free-field vibrations and building foundations vibrations. The sources of considered vibrations were mine-induced rockbursts resulting from underground exploitation of copper ore. Only records induced by rockbursts with energy higher than 10 6 J and horizontal components of peak ground accelerations larger than 10cm/s 2 are analysed. Epicentral distances of considered mining shocks are in the range re = 270-5839 m and energies are in the range En = 1•10 6-2•10 9 J. Dimensionless acceleration response spectra (β) as well as dimensional acceleration response spectra (S a) from the horizontal vibrations were taken into account. The focus is on residential buildingsmediumrise building and high-rise building. The results of analyses show that the epicentral distance of mining shock can have a significant impact on the transmission of response spectra from the free-field to the residential building foundations (medium-rise building and high-rise building). This effect is more visible in the case of curves RRS(β) determined using dimensionless acceleration response spectra β than curves RRS(S a) calculated for corresponding pairs for dimensional spectra S a. The appropriate conclusions regarding the influence of mining tremors energies also have been achieved.
E3S Web of Conferences
The paper compares the results of an approximate evaluation of mining tremors harmfulness performed on the basis of free-field and simultaneously measured building foundation vibrations. The focus is on the office building located in the Upper Silesian Basin (USB). The empirical Mining Intensity Scale GSI-GZWKW-2012 has been applied to classify the harmfulness of the rockbursts. This scale is based on the measurements of free-field vibrations but, for research purposes, it was also used in the cases of building foundation vibrations. The analysis was carried out using the set of 156 pairs ground – foundation of velocity vibration records as well as the set of 156 pairs of acceleration records induced by the same mining tremors.
Technical Transactions, 2017
The paper deals with the analysis of measurements of vibrations induced by mining rockbursts in the Legnica–Glogow Copperfield District (LGCD) to estimate the influence of mining tremor epicentral distance on the curve of relationship (RRS) between the response spectra from the simultaneously measured ground and building foundations vibrations. Non-dimension acceleration response spectra (β) as well as dimension acceleration response spectra (Sa) from the horizontal vibrations were taken into account. The focus is on apartment buildings – medium-rise and high-rise buildings. Additionally, a comparison of conclusions of research carried out in the case of response spectra with the corresponding earlier results regarding the reduction of maximum values of accelerations of vibrations during the transfer from the ground to building foundations were performed.
A system to mitigate deep mine tremor effects in the design of civil infrastructure
International Journal of Rock Mechanics and Mining Sciences, 2015
Deep mining may induce quakes reaching magnitude m L of 4.5 to 5.5 and leading to surface ground motion with Modified Mercalli intensities up to VIII. Such strong ground motions may cause serious damages in civil infrastructure in the vicinity of mines. However any adaptation of a classic seismic code in design faces an impending problem of differences in spectral content and duration between the surface records of the rockbursts and natural earthquakes, as well as in their different risk definitions. This paper presents a system to define design seismic load based on forecasted surface horizontal particle velocity from the rockbursts expected during the planned mining activities. Such forecasts are routinely prepared by the geophysical mine services. Respective seismic load may then be applied in the design of buildings and other structures to mitigate the rockburst induced seismic effects on them. For this purpose the European seismic code, Eurocode 8, is adapted.
Example Building Damage Caused by Mining Exploitation in Disturbed Rock Mass
Studia Geotechnica et Mechanica, 2013
Issues concerning protection of buildings against the impact of underground coal mining pose significant scientific and engineering challenges. In Poland, where mining is a potent and prominent industry assuring domestic energy security, regions within reach of mining influences are plenty. Moreover, due to their industrial character they are also densely built-up areas. Because minerals have been extracted on an industrial scale in majority of those areas for many years, the rock mass structure has been significantly disturbed. Hence, exploitation of successive layers of multi-seam deposits might cause considerable damage - both in terms of surface and existing infrastructure networks. In the light of those facts, the means of mining and building prevention have to be improved on a regular basis. Moreover, they have to be underpinned by reliable analyses holistically capturing the comprehensive picture of the mining, geotechnical and constructional situation of structures. Scientif...