Landslides are a frequent phenomenon on mountain Elgon, particularly in Bududa district on the SW side of this extinct shield volcano. Landslides have led to the destruction of property and loss of life we, therefore,...Landslides are a frequent phenomenon on mountain Elgon, particularly in Bududa district on the SW side of this extinct shield volcano. Landslides have led to the destruction of property and loss of life we, therefore, need to monitor them. Monitoring how landslides build-up makes it possible to timely evacuate people and build barriers to protect property against damage by landslides. Residents in Bududa have reported cracks developing in the ground and houses. These cracks continue to grow, suggesting a future catastrophic event. Such an event may resemble the 2010 landslide in Bududa, which killed approximately 450 people and destroyed much property. In order to mitigate the consequences of a new landslide as much as possible, we monitored ground motion in Bududa in eleven stations from June 2018 to June 2019. Six-hour session GPS observations were made, and deformation was determined over the observation period, June to September 2018, September to November 2018, November 2018 to February 2019 and February to June 2019. A congruency test was performed to determine how significant the deformation was. It appeared that the ground deformation differed largely at various monitored stations, ranging from 0.004 to 0.076 m, 0.001 to 0.067 m and 0 to 0.078 m in the East, North and vertical directions respectively. The values indicate that most slopes in the district are unstable, particularly in the wet seasons, which implies that future landslides pose a high risk for society.展开更多
This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in differe...This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a MSA are investigated numerically. The partial ground plane removal reduces the backlobe radiation of the MSA by suppressing the surface wave diffraction from the edges of the antenna ground plane. For further improving the front-to-back (F/B) ratio of the MSA, a new soft-surface configuration consisting of an array of stand-up split ring resonators (SRRs) are placed on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 9.7 dB has been achieved experimentally for our proposed MSA.展开更多
As the continuation study on amplification of in-plane seismic ground motion by underground group cavities in layered half-space, this study extends to the case of poroelastic half-space with dry poroelastic and satur...As the continuation study on amplification of in-plane seismic ground motion by underground group cavities in layered half-space, this study extends to the case of poroelastic half-space with dry poroelastic and saturated poroelastic soil layers. The influence of poroelastic layers on the amplification of seismic ground motion is studied both in frequency domain and time domain using indirect boundary element method (IBEM). It is shown that for the example of a saturated poroelastic site in Tianjin under the excitation of Taft wave and El Centro wave, the amplification of seismic ground motion in poroelastic case is slightly smaller than that in the elastic case, and the amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 38.8% and 64.6%; the predominant period of response spectra in poroelastic case becomes shorter to some extent compared with that in the elastic case. It is suggested that the effect of underground group cavities in poroelastic half-space on design seismic ground motion should be considered.展开更多
Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect ...Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect of cavity interval and spectrum of incident waves on the amplification are studied by numerical examples. It is shown that there may be large interaction between cavities, and group cavities with certain intervals may have significant amplification to seismic ground motion. The amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 45.2% and 84.4%, for an example site in Tianjin, under the excitation of Taft wave and El Centro wave; and group cavities may also affect the spectra of the seismic ground motion. It is suggested that the effect of underground group cavities on design seismic ground motion should be considered.展开更多
This paper considers the processes of activation in ground subsidence movements in flooding mine workings of mines being liquidated in two districts in Donetsk city on the area of more than 60km^2. A concept is give...This paper considers the processes of activation in ground subsidence movements in flooding mine workings of mines being liquidated in two districts in Donetsk city on the area of more than 60km^2. A concept is given to build up control network of geomechanical monitoring in conditions of existing old mining operations at shallow depths (down to 100m), strong damages of objects of urban building. Given are GPS network structure, layouts for location of basic and local profile lines, special control stations for monitoring ground subsidence movements over the territory of mines being flooded. Results of the series of observations made are discussed and their accuracy is analyzed.展开更多
The base vector between 2 poins and a high-precision geodetic height difference can be obtained by GPS. If the geodetic height of a point is known, the geodetic height of each observation point in a net can be obtaine...The base vector between 2 poins and a high-precision geodetic height difference can be obtained by GPS. If the geodetic height of a point is known, the geodetic height of each observation point in a net can be obtained. When surveying the subsidence value in the mining-induced ground subsidence, the change of the height of monitoring point is needed. On the above theoretical basis, the problem involved in GPS observation of mining-induced ground subsidence and their counter measures were discussed, and an introduction was made that the subsidence value obtained in the monitoring mining-induced ground subsidence can use the change of height of geodetic as a alternative, the result of check on the accuracy and reliability of repetitions observations was analysed. Finally, the effect of errors on accuracy of GPS observation and their reduction measures were elaborated.展开更多
To trace the potential hazards of open-pit slope in Longshou mine,global positioning system(GPS) is applied to monitoring ground movement and deformation induced by transition from open-pit to underground mining.Throu...To trace the potential hazards of open-pit slope in Longshou mine,global positioning system(GPS) is applied to monitoring ground movement and deformation induced by transition from open-pit to underground mining.Through long-term monitoring from 2003 to 2008,huge amounts of data were acquired.Monitoring results show that large-scale ground movement and deformation have occurred in mining area,and the movement area is ellipse-shaped.The displacement boundary of settlement trough is 2.0 km long along the exploratory line,and 1.5 km long along the strike of ore body.GPS monitoring results basically agree with the practical deformation state of open-pit slope.It is indicated that the long-term GPS monitoring is an effective way to understand the mechanism of ground movement and deformation in mine area.展开更多
The April 25,2015 Mw7.8 Nepal earthquake was successfully recorded by Crustal Movement Observation Network of China(CMONOC) and Nepal Geodetic Array(NGA).We processed the high-rate GPS data(1 Hz and 5 Hz) by using rel...The April 25,2015 Mw7.8 Nepal earthquake was successfully recorded by Crustal Movement Observation Network of China(CMONOC) and Nepal Geodetic Array(NGA).We processed the high-rate GPS data(1 Hz and 5 Hz) by using relative kinematic positioning and derived dynamic ground motions caused by this large earthquake.The dynamic displacements time series clearly indicated the displacement amplitude of each station was related to the rupture directivity.The stations which located in the direction of rupture propagation had larger displacement amplitudes than others.Also dynamic ground displacement exceeding 5 cm was detected by the GPS station that was 2000 km away from the epicenter.Permanent coseismic displacements were resolved from the near-field high-rate GPS stations with wavelet decomposition-reconstruction method and P-wave arrivals were also detected with S transform method.The results of this study can be used for earthquake rupture process and Earthquake Early Warning studies.展开更多
A single layer single element rectangular microstrip antenna on ridge ground plane for improved bandwidth is theoretically investigated with a view to develop a concrete physical insight in to the phenomenon. The simp...A single layer single element rectangular microstrip antenna on ridge ground plane for improved bandwidth is theoretically investigated with a view to develop a concrete physical insight in to the phenomenon. The simple single element probe fed rectangular microstrip antenna fabricated on conventional PTFE (Poly Tetra Fluride Ethelene) substrate have many advantages except its narrow bandwidth. The present study proposes the technique to control the resonant modes of a microstrip antenna for yielding better bandwidth using transverse resonance method. The present antenna is designed to fabricate on ridge ground plane which has been compared with conventional structure and around 6% - 7% improvement in bandwidth is revealed. The detailed variation of radiation pattern across its frequency band has been studied and presented in this paper. The proposed idea has been verified through a commercial software package (High Frequency Structure Simulator) for a patch operating in X band and explained quantitatively. The electric surface current distribution over the patch surface for both the conventional and proposed antenna is presented to explain the broad banding effect physically.展开更多
This paper presents an application of stitched ground plane for microstrip patch antenna design. In this work Matlab interface to computer embroidery techniques were used to implement the felt and denim substrates on ...This paper presents an application of stitched ground plane for microstrip patch antenna design. In this work Matlab interface to computer embroidery techniques were used to implement the felt and denim substrates on microstrip patch antenna. These antennas were simulated using a commercial full 3D electromagnetic CST Microwave Studio 2019. A method to optimize the stitch patterns with conductive thread for antenna ground plane for 2.45 GHz industrial, scientific, and medical (ISM) band and 5 GHz wearable wireless local area networks (WLAN) frequencies was achieved. Rigid and flexible wearable antennas (microstrip patch antennas) were fabricated using the stitched ground plane. The electrical resistance was reduced between the meshes during the stitching design process. Results in terms of bandwidth, radiation patterns and reflection coefficients (S<sub>11</sub>) are presented.展开更多
This work explores the optimal mesh structure, stitch density and production technique of stitched ground plane for microstrip patch antenna. Meshed ground plane was used as a generic problem. A stitched ground plane ...This work explores the optimal mesh structure, stitch density and production technique of stitched ground plane for microstrip patch antenna. Meshed ground plane was used as a generic problem. A stitched ground plane is pro-posed and designed using Matlab interface to computer embroidery. Using the meshed or stitched ground plane as a case study, the resistance between meshes was analysed and measured. The equivalent resistance between nodes is a function of their distance apart. A finite resistive grid was simulated and compared to measured sets of data. A microstrip patch antenna with stitched ground shows comparable performance to the conventional etched ground of the size in terms of bandwidth. The stitched ground plane has a higher band-width than the etched copper ground plane because of the increased thickness of the substrate. Thus, it can be concluded that the use of the interface method shows the possibilities of controlling the stitch density and distances between mesh nodes. The interface increases the stitching density and reduces the elec-trical resistance between mesh nodes making the antennas flexible and weara-ble. The functionality of these antenna samples has been tested and validated using microstrip patch ground at 2.45 GHz and 5 GHz. Measurement results on the proposed stitched ground planes were compared with the theory of infinite resistive network that shows good agreement.展开更多
Based on the effective medium theory, the triangular ground plane cloak can be realized by thin layered systems. Two solutions of parameter setting of the layered cloak are suggested to demonstrate the invisibility pe...Based on the effective medium theory, the triangular ground plane cloak can be realized by thin layered systems. Two solutions of parameter setting of the layered cloak are suggested to demonstrate the invisibility performance of a hybrid incoming wave. The hybrid parameters are derived from the equivalent of both anisotropies of permittivity and permeability to the alternating layers. The performance of the designed layered cloak is validated by both TM and TE wave simulations with near-field distributions and average scattering power outflows on an observation semicircle. From the simulation results, the layered cloak with both hybrid parameters and improved hybrid parameters can reflect the incoming TM/TE waves in a specular direction, and the latter behaves with a better overall invisibility performance.展开更多
Long-term field monitoring finds that serious surface subsidence can still occur even if the high strength cemented fill method is adopted.Combining the results of numerical simulations with global position system(GPS...Long-term field monitoring finds that serious surface subsidence can still occur even if the high strength cemented fill method is adopted.Combining the results of numerical simulations with global position system(GPS)monitoring,we took a typical filling mining mine with a steeply inclined ore body as an example,and explored its ground subsidence mechanism.The results show that the ground subsidence caused by the mining of steep ore body is characterized by two settlement centers and a significantly uneven spatial distribution,which is visibly different from ground subsidence characteristic of the coal mine.The subsidence on the hanging wall is much larger than that on the footwall,and the settlement center tends to move to the hanging wall with the increase of mining depth.The backfill improves the strength and surrounding rock bearing capacity,which leads to a lag of about 3 years of the subsidence.However,under the actions of continuous and repeated mining disturbances,the supporting effect of the backfill can only reduce the amplitude of the deformation,but it cannot prevent the occurrence of settlement.展开更多
The attenuation relationship of ground motion based on seismology has always been a front subject of engineering earthquake.Among them,the regional finite-fault source model is very important.In view of this point,the...The attenuation relationship of ground motion based on seismology has always been a front subject of engineering earthquake.Among them,the regional finite-fault source model is very important.In view of this point,the general characteristics of regional seism-tectonics,including the dip and depth of the fault plane,are emphasized.According to the statistics of regional seism-tectonics and focal mechanisms in Sichuan,China,and the sensitivity of estimated peak ground acceleration(PGA)attenuation is analyzed,and the dip angle is taken as an average of 70°.Based the statistics of the upper crustal structure and the focal depth of regional earthquakes,the bottom boundary of the sedimentary cover can be used as the upper limit for estimating the depth of upper-edge.The analysis shows that this value is sensitive to PGA.Based on the analysis of geometric relations,the corresponding calculation formula is used,and a set of concepts and steps for building the regional finite-fault source model is proposed.The estimation of source parameters takes into account the uncertainty,the geometric relationship among parameters and the total energy conservation.Meanwhile,a set of reasonable models is developed,which lay a foundation for the further study of regional ground motion attenuation based on seismology.展开更多
文摘Landslides are a frequent phenomenon on mountain Elgon, particularly in Bududa district on the SW side of this extinct shield volcano. Landslides have led to the destruction of property and loss of life we, therefore, need to monitor them. Monitoring how landslides build-up makes it possible to timely evacuate people and build barriers to protect property against damage by landslides. Residents in Bududa have reported cracks developing in the ground and houses. These cracks continue to grow, suggesting a future catastrophic event. Such an event may resemble the 2010 landslide in Bududa, which killed approximately 450 people and destroyed much property. In order to mitigate the consequences of a new landslide as much as possible, we monitored ground motion in Bududa in eleven stations from June 2018 to June 2019. Six-hour session GPS observations were made, and deformation was determined over the observation period, June to September 2018, September to November 2018, November 2018 to February 2019 and February to June 2019. A congruency test was performed to determine how significant the deformation was. It appeared that the ground deformation differed largely at various monitored stations, ranging from 0.004 to 0.076 m, 0.001 to 0.067 m and 0 to 0.078 m in the East, North and vertical directions respectively. The values indicate that most slopes in the district are unstable, particularly in the wet seasons, which implies that future landslides pose a high risk for society.
文摘This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a MSA are investigated numerically. The partial ground plane removal reduces the backlobe radiation of the MSA by suppressing the surface wave diffraction from the edges of the antenna ground plane. For further improving the front-to-back (F/B) ratio of the MSA, a new soft-surface configuration consisting of an array of stand-up split ring resonators (SRRs) are placed on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 9.7 dB has been achieved experimentally for our proposed MSA.
基金supported by National Natural Science Foundation of China under grant No. 50978183Key Project for Applied Basic Research of Tianjin Municipality under Grant No. 12JCZDJC29000
文摘As the continuation study on amplification of in-plane seismic ground motion by underground group cavities in layered half-space, this study extends to the case of poroelastic half-space with dry poroelastic and saturated poroelastic soil layers. The influence of poroelastic layers on the amplification of seismic ground motion is studied both in frequency domain and time domain using indirect boundary element method (IBEM). It is shown that for the example of a saturated poroelastic site in Tianjin under the excitation of Taft wave and El Centro wave, the amplification of seismic ground motion in poroelastic case is slightly smaller than that in the elastic case, and the amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 38.8% and 64.6%; the predominant period of response spectra in poroelastic case becomes shorter to some extent compared with that in the elastic case. It is suggested that the effect of underground group cavities in poroelastic half-space on design seismic ground motion should be considered.
基金supported by National Natural Science Foundation of China under grant No. 50978183Tianjin Key Project for Applied Basic Research under grant No. 12JCZDJC29000
文摘Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect of cavity interval and spectrum of incident waves on the amplification are studied by numerical examples. It is shown that there may be large interaction between cavities, and group cavities with certain intervals may have significant amplification to seismic ground motion. The amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 45.2% and 84.4%, for an example site in Tianjin, under the excitation of Taft wave and El Centro wave; and group cavities may also affect the spectra of the seismic ground motion. It is suggested that the effect of underground group cavities on design seismic ground motion should be considered.
文摘This paper considers the processes of activation in ground subsidence movements in flooding mine workings of mines being liquidated in two districts in Donetsk city on the area of more than 60km^2. A concept is given to build up control network of geomechanical monitoring in conditions of existing old mining operations at shallow depths (down to 100m), strong damages of objects of urban building. Given are GPS network structure, layouts for location of basic and local profile lines, special control stations for monitoring ground subsidence movements over the territory of mines being flooded. Results of the series of observations made are discussed and their accuracy is analyzed.
基金FoundatianitemProject (99 mining 20267) supported by Coal Science Fund .
文摘The base vector between 2 poins and a high-precision geodetic height difference can be obtained by GPS. If the geodetic height of a point is known, the geodetic height of each observation point in a net can be obtained. When surveying the subsidence value in the mining-induced ground subsidence, the change of the height of monitoring point is needed. On the above theoretical basis, the problem involved in GPS observation of mining-induced ground subsidence and their counter measures were discussed, and an introduction was made that the subsidence value obtained in the monitoring mining-induced ground subsidence can use the change of height of geodetic as a alternative, the result of check on the accuracy and reliability of repetitions observations was analysed. Finally, the effect of errors on accuracy of GPS observation and their reduction measures were elaborated.
基金Supported by the National Natural Science Foundation of China (40972197,41002107, 41030750)the Program of Knowledge Innovation of the Chinese Academy of Sciences (KZCX2-YW-Q03-02)
文摘To trace the potential hazards of open-pit slope in Longshou mine,global positioning system(GPS) is applied to monitoring ground movement and deformation induced by transition from open-pit to underground mining.Through long-term monitoring from 2003 to 2008,huge amounts of data were acquired.Monitoring results show that large-scale ground movement and deformation have occurred in mining area,and the movement area is ellipse-shaped.The displacement boundary of settlement trough is 2.0 km long along the exploratory line,and 1.5 km long along the strike of ore body.GPS monitoring results basically agree with the practical deformation state of open-pit slope.It is indicated that the long-term GPS monitoring is an effective way to understand the mechanism of ground movement and deformation in mine area.
基金supported by Director Foundation of Institute of Seismology,China Earthquake Administration(IS201426142)National Natural Science Foundation of China(41541029,41574017, 41274027)+1 种基金Natural Science Foundation of HuBei Province (2015CFB642)provided by Crustal Movement Observation Network of China(CMONOC) and UNAVCO
文摘The April 25,2015 Mw7.8 Nepal earthquake was successfully recorded by Crustal Movement Observation Network of China(CMONOC) and Nepal Geodetic Array(NGA).We processed the high-rate GPS data(1 Hz and 5 Hz) by using relative kinematic positioning and derived dynamic ground motions caused by this large earthquake.The dynamic displacements time series clearly indicated the displacement amplitude of each station was related to the rupture directivity.The stations which located in the direction of rupture propagation had larger displacement amplitudes than others.Also dynamic ground displacement exceeding 5 cm was detected by the GPS station that was 2000 km away from the epicenter.Permanent coseismic displacements were resolved from the near-field high-rate GPS stations with wavelet decomposition-reconstruction method and P-wave arrivals were also detected with S transform method.The results of this study can be used for earthquake rupture process and Earthquake Early Warning studies.
文摘A single layer single element rectangular microstrip antenna on ridge ground plane for improved bandwidth is theoretically investigated with a view to develop a concrete physical insight in to the phenomenon. The simple single element probe fed rectangular microstrip antenna fabricated on conventional PTFE (Poly Tetra Fluride Ethelene) substrate have many advantages except its narrow bandwidth. The present study proposes the technique to control the resonant modes of a microstrip antenna for yielding better bandwidth using transverse resonance method. The present antenna is designed to fabricate on ridge ground plane which has been compared with conventional structure and around 6% - 7% improvement in bandwidth is revealed. The detailed variation of radiation pattern across its frequency band has been studied and presented in this paper. The proposed idea has been verified through a commercial software package (High Frequency Structure Simulator) for a patch operating in X band and explained quantitatively. The electric surface current distribution over the patch surface for both the conventional and proposed antenna is presented to explain the broad banding effect physically.
文摘This paper presents an application of stitched ground plane for microstrip patch antenna design. In this work Matlab interface to computer embroidery techniques were used to implement the felt and denim substrates on microstrip patch antenna. These antennas were simulated using a commercial full 3D electromagnetic CST Microwave Studio 2019. A method to optimize the stitch patterns with conductive thread for antenna ground plane for 2.45 GHz industrial, scientific, and medical (ISM) band and 5 GHz wearable wireless local area networks (WLAN) frequencies was achieved. Rigid and flexible wearable antennas (microstrip patch antennas) were fabricated using the stitched ground plane. The electrical resistance was reduced between the meshes during the stitching design process. Results in terms of bandwidth, radiation patterns and reflection coefficients (S<sub>11</sub>) are presented.
文摘This work explores the optimal mesh structure, stitch density and production technique of stitched ground plane for microstrip patch antenna. Meshed ground plane was used as a generic problem. A stitched ground plane is pro-posed and designed using Matlab interface to computer embroidery. Using the meshed or stitched ground plane as a case study, the resistance between meshes was analysed and measured. The equivalent resistance between nodes is a function of their distance apart. A finite resistive grid was simulated and compared to measured sets of data. A microstrip patch antenna with stitched ground shows comparable performance to the conventional etched ground of the size in terms of bandwidth. The stitched ground plane has a higher band-width than the etched copper ground plane because of the increased thickness of the substrate. Thus, it can be concluded that the use of the interface method shows the possibilities of controlling the stitch density and distances between mesh nodes. The interface increases the stitching density and reduces the elec-trical resistance between mesh nodes making the antennas flexible and weara-ble. The functionality of these antenna samples has been tested and validated using microstrip patch ground at 2.45 GHz and 5 GHz. Measurement results on the proposed stitched ground planes were compared with the theory of infinite resistive network that shows good agreement.
基金supported partly by the Open Research Program in State Key Laboratory of Millimeter Waves of China (Grant No. K201103)partly by the National Natural Science Foundation of China (Grant No. 60971122)partly by the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2011727)
文摘Based on the effective medium theory, the triangular ground plane cloak can be realized by thin layered systems. Two solutions of parameter setting of the layered cloak are suggested to demonstrate the invisibility performance of a hybrid incoming wave. The hybrid parameters are derived from the equivalent of both anisotropies of permittivity and permeability to the alternating layers. The performance of the designed layered cloak is validated by both TM and TE wave simulations with near-field distributions and average scattering power outflows on an observation semicircle. From the simulation results, the layered cloak with both hybrid parameters and improved hybrid parameters can reflect the incoming TM/TE waves in a specular direction, and the latter behaves with a better overall invisibility performance.
基金support from the National Natural Science Foundation of China(Grant Nos.42072305 and 41831293)。
文摘Long-term field monitoring finds that serious surface subsidence can still occur even if the high strength cemented fill method is adopted.Combining the results of numerical simulations with global position system(GPS)monitoring,we took a typical filling mining mine with a steeply inclined ore body as an example,and explored its ground subsidence mechanism.The results show that the ground subsidence caused by the mining of steep ore body is characterized by two settlement centers and a significantly uneven spatial distribution,which is visibly different from ground subsidence characteristic of the coal mine.The subsidence on the hanging wall is much larger than that on the footwall,and the settlement center tends to move to the hanging wall with the increase of mining depth.The backfill improves the strength and surrounding rock bearing capacity,which leads to a lag of about 3 years of the subsidence.However,under the actions of continuous and repeated mining disturbances,the supporting effect of the backfill can only reduce the amplitude of the deformation,but it cannot prevent the occurrence of settlement.
基金National Natural Science Foundation of China(51678540,51778197)Heilongjiang Province Key Research and Development Program Guidance Project of China(GZ20220028)+2 种基金Heilongjiang Bayi Agricultural University Support Program for San Heng San Zong(ZRCPY202225)Heilongjiang Bayi Agricultural University Project of Scientific Research Initiation Plan for Learning and Introducing Talents of China(XYB2014-06)Daqing Science and Technology Plan Project of China(zd-2021-86).
文摘The attenuation relationship of ground motion based on seismology has always been a front subject of engineering earthquake.Among them,the regional finite-fault source model is very important.In view of this point,the general characteristics of regional seism-tectonics,including the dip and depth of the fault plane,are emphasized.According to the statistics of regional seism-tectonics and focal mechanisms in Sichuan,China,and the sensitivity of estimated peak ground acceleration(PGA)attenuation is analyzed,and the dip angle is taken as an average of 70°.Based the statistics of the upper crustal structure and the focal depth of regional earthquakes,the bottom boundary of the sedimentary cover can be used as the upper limit for estimating the depth of upper-edge.The analysis shows that this value is sensitive to PGA.Based on the analysis of geometric relations,the corresponding calculation formula is used,and a set of concepts and steps for building the regional finite-fault source model is proposed.The estimation of source parameters takes into account the uncertainty,the geometric relationship among parameters and the total energy conservation.Meanwhile,a set of reasonable models is developed,which lay a foundation for the further study of regional ground motion attenuation based on seismology.
