Dynamic Response of Soils Influenced by Seismic Activities

doi:10.21203/rs.3.rs-4436331/v1

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Dynamic Response of Soils Influenced by Seismic Activities

https://doi.org/10.21203/rs.3.rs-4436331/v1

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The study investigated the dynamic soil properties of Delta and Akwa Ibom States in Niger Delta region of Nigeria as a function of seismic activities. The down-hole seismic test was used to determine the response of the soils. The results showed that young modulus increases with increase in depth, which ranged from 2817.5 to 3178.27kPa across the sites at depth of 30m. Also, shear wave velocity generally increases with increase in depth. The shear wave velocity results obtained from the experiment across the sites ranged from 130-283m/s, 139-262m/s,141-247m/s, 128-261m/s and 124-289m/s for Ikot Abasi, Ibagwa, Ibiaku Offot, Aboh and Afor Ogbodigbo respectively. Like the shear wave velocity, P-wave velocity generally increases with increase in depth, which is over twice the values of shear wave velocity. The P-wave velocity ranged from 326-676m/s across the sites. The void ratio was observed to be constant at certain range of depth in the soil strata, and in most cases, it does not increase correspondingly with depth. The void ratio results ranged from 0.655-0.813, 0.652-0.805, 0.664-0.794, 0.65-0.82 and 0.651-0.798 for Ikot Abasi, Ibagwa, Ibiaku Offot, Aboh and Afor Ogbodigbo sites respectively. Unlike void ratio, Poisson’s ratio fluctuates with depth, with values ranging from 0.249-0.353, 0.253-0.351, 0.308-0.357, 0.254-0.371 and 0.241-0.370 for Ikot Abasi, Ibagwa, Ibiaku Offot, Aboh and Afor Ogbodigbo sites respectively. Based on the observations on the dynamic response of the soils, the Niger Delta region, being an oil hub center, is susceptible to earthquake, which could be triggered with time if over stressed by heavy load and seismic activities.

Seismic Activities

Dynamic Response

Soil properties

Young Modulus

Shear Wave Velocity

Globally, natural disasters have become a great challenge to humans. These disasters ranged from the failures of embankments, natural slopes, earth structures and foundations; and they have been attributed to the liquefaction of sands, landslides and slope instability. However, these natural disasters are a result of seismic effects and only occur in a geographical area with distinct characteristics. The geotechnical seismic response is a function of intense motion due to the stress-strain response of soils. The parameters of soil mechanical properties of damping ratio (D), shear modulus (G), shear wave velocity (Vs) and Poisson's ratio are those connected with dynamic loading.

Earthquakes and other seismic activities can have a significant impact on the behavior and response of soils, particularly with respect to liquefaction potential. Liquefaction is a phenomenon that occurs when saturated, loose sandy or silty soils lose their strength and stiffness during strong ground shaking, leading to severe damage to structures and infrastructure [1]. Understanding the dynamic response of soils is crucial for assessing and mitigating the risks associated with seismic events.

Globally, natural disasters have become a major challenge, and these disasters can be attributed to the liquefaction of sands, landslides, and slope instability [2]. The geotechnical seismic response is a function of intense motion due to the stress-strain response of soils, and parameters such as damping ratio (D), shear modulus (G), shear wave velocity (Vs), and Poisson's ratio are connected with dynamic loading.

Seismic activities, including earthquakes, earth tremors, tsunamis, floods, and cyclones, can cause extensive damage to the environment, infrastructure, and loss of life [3]. Historical and notable earthquakes or earth tremors in Nigeria have been documented, and these events challenge the long-held belief that Nigeria is seismically safe [3–8]. The possible mechanisms for these intraplate tremors could be due to the regional stress created by the West African Craton and the various episodes of magmatic intrusions and other tectonic activities [7, 8].

Researchers have examined seismic data, developed models for estimating event magnitudes, and investigated the relationship between stresses, complex faults, and intraplate earthquakes in Nigeria [9–12]. The findings have highlighted the significant seismic hazards in some regions, such as Cairo, Egypt, where a peak ground acceleration of 0.15-0.2g with a 10% probability of exceedance in 50 years has been estimated [12].

Studies on the 2016 M5.9 Lake Victoria earthquake and the 2003 Mw 6.8 Boumerdes, Algeria earthquake have provided valuable insights into the source features and effects of these rare, large earthquakes in East Africa and North Africa, respectively [13, 14].

Historical earthquakes or earth tremors in Nigeria have been documented, and the intensities of these events ranged from III to VI based on the Modified Mercalli Intensity Scale [3–6, 15–20]. This study investigated the dynamic soil properties of Delta and Akwa Ibom States in the Niger Delta region of Nigeria as a function of seismic activities.

One of the key factors in evaluating the liquefaction potential of soils is the shear wave velocity (Vs), which is influenced by the soil's density, stiffness, and degree of saturation [21, 22]. Researchers have developed various methods to estimate the liquefaction resistance of soils based on Vs measurements, including probabilistic and deterministic approaches [23–28].

In addition to Vs, other geotechnical and geophysical techniques, such as cone penetration tests (CPT), standard penetration tests (SPT), electrical resistivity imaging (ERI), and multichannel analysis of surface waves (MASW), have been employed to characterize the subsurface conditions and assess the liquefaction potential of soils [29–34].

The dynamic response of soils can be influenced by a range of factors, including soil type, gradation, density, and degree of saturation [35]. In seismically active areas like Nigeria, understanding the local soil conditions and their susceptibility to liquefaction is crucial for development and infrastructure planning [36–41].

The assessment of liquefaction potential often involves a combination of field investigations, laboratory testing, and numerical modelling [42–44]. Integrated geophysical and geotechnical studies have been employed to characterize the subsurface conditions and evaluate the liquefaction risk in various regions of Nigeria [7, 45, 46]. These studies have highlighted the importance of site-specific investigations and the need for a comprehensive approach to understanding the dynamic behavior of soils in seismically active areas.

2.1 Sample Location

The soil samples for this study were collected from 2 States within the Niger Delta region of Nigeria, as described by [1]. The sampling locations in Akwa Ibom State include Ikot Abasi Town, Ikpa Ebkwe District, Ikot Abasi Local Government Area (latitude 4.5739° N and longitude 7.5789° E), Ibagwa Town, Abak Urban District, Abak Local Government Area (latitude 4.9003° N and longitude 7.7969° E), and Ibiaku Offot Town, Offot District, Uyo Local Government Area (latitude 5.0583° N and longitude 7.9108° E) [1]. The sampling sites in Delta State are Aboh Town, Ndokwa East Local Government Area (latitude 5.5494° N and longitude 6.5276° E) and Afor Ogbodigbo Town, Ndokwa East Local Government Area (latitude 5.4633° N and longitude 6.8885° E) [1]. These strategic locations within the Niger Delta region were selected to provide a comprehensive understanding of the dynamic soil properties in this geologically significant area.

The selection of these sampling sites was informed by the region's history of seismic activities, as documented in various studies [2–6]. The Niger Delta region, known for its oil and gas resources, has experienced a number of earthquake events and earth tremors in the past, which have raised concerns about the region's susceptibility to seismic hazards [2–6]. By investigating the dynamic soil properties at these specific locations, the researchers aimed to gain insights into the potential risks and implications of seismic activities in this economically important region of Nigeria.

2.2 Soil Sample Collection

The soil samples for this study were collected through a comprehensive subsurface exploration process at the designated sites [1]. This process involved drilling and deep boring using the standard penetration test (SPT) method [7]. Both in-situ field tests and laboratory tests were conducted to thoroughly assess the dynamic soil properties of the samples [1].

The collected soil samples were subjected to a series of preparatory steps prior to testing. The samples were first dried, crushed, and sieved through a No. 4 (4.75 mm) sieve, with the standard and known weights of the samples recorded [1]. The samples were then mixed with an appropriate amount of water to represent their natural water content state [1]. This step ensured that the soil samples were representative of the in-situ conditions at the sampling locations.

Following the sample preparation, the soil specimens were remolded to their field density and natural moisture content stage [1]. The samples were then carefully measured to a standard size of 20 mm height and 70 mm diameter, and placed in a rubber membrane [1]. These prepared specimens were mounted on the bottom plate of a cyclic direct simple shear machine, with confined rings to control the lateral deformation during the consolidation stages [1].

The comprehensive sample collection and preparation procedures adopted in this study [1] were essential to ensure the accuracy and reliability of the subsequent dynamic soil property tests. By following these standardized protocols, the researchers were able to obtain representative samples that accurately reflected the in-situ soil conditions in the Niger Delta region, allowing for a thorough investigation of the soils' response to seismic activities [7, 8]

2.3 Seismic Bore-hole Test

The seismic borehole test employed in this study [1] enabled a more comprehensive characterization of the lithological and groundwater flow conditions compared to conventional methods such as cuttings, split spoon samples, or core samples [9, 10]. This technique holds a distinct advantage in its ability to describe subsurface conditions in greater detail than surface-based methods [1].

Through the cross-hole seismic (CS) measurements, the researchers were able to determine the dynamic elastic moduli, including the shear modulus, Young's modulus, and Poisson's ratio [1]. This field-based test involved the installation and instrumentation of boreholes to directly measure the wave propagation velocity [1].

The specific equations used in the analysis of the dynamic soil properties are as follows [1]:

Variation of Young Modulus

E = α(σ′m) β (1)

Variation of Shear Wave Velocity

Vs = α(σ′m) β (2)

Variation of P-Wave Velocity

Vp = α(σ′m) β (3)

Variation of Void Ratio (4)

e = e0 - Cc log(σ′m)

Variation of Poisson's Ratio

ν = ν0 + α(σ′m) β (5)

The shear wave velocity and P-wave velocity were determined using the down-hole seismic (DS) test method [1]. This approach involved the use of a hammer source at the surface to impact a wooden plank, generating both shear and compressive waves [1]. The plank was coupled to the ground near the borehole, and the impacts were directed in both the vertical and horizontal directions [1]. The resulting energy from these impacts was then received by a pair of matching three-component geophone receivers, which were lowered into the borehole and spaced 1.5 to 3 meters apart [1].

The comprehensive seismic borehole testing methods employed in this study [1] provided valuable insights into the dynamic soil properties and their spatial variations, which are crucial for understanding the region's potential seismic hazards and their implications for infrastructure planning and development [11, 12].

The seismic down-hole dynamic soil properties of the various locations in Niger Delta region of Nigeria was studied based on young modulus, shear wave velocity, p-wave velocity, void ratio and Poisson’s ratio.

3.1 Variation of Young Modulus

The study of Young's modulus, as depicted in Fig. 1, yielded valuable insights into the dynamic response of soil and plays a key role in observing the material's behavior [1]. A close examination of the results derived from the experiment demonstrated that the stiffness of the soil increases with depth. The strength of Young's modulus may vary from 117.15 to 2817.5 kPa over a range of 0.95 to 30 meters at the Ikot Abasi site, while corresponding values of 120.95 to 3178.27 kPa and 121.34 to 3132.6 kPa were observed at the Ibagwa and Ibiaku Offot sites respectively [1]. At the Aboh and Afor Ogbodigbo sites, the Young's modulus further ranged from 121.36 to 3113.92 kPa and 110.17 to 2921.98 kPa respectively [1]. The examination of Young's modulus in varying soil conditions can be attributed to various reasons, such as the pressure of the overlying soil layers on the underlying layers which leads to increased compaction and stiffness [2, 3].

Different soil compositions and geological formations present at different depths, as well as conditions like moisture content, porosity, and human or natural disturbances can also affect the stiffness of the soil [4, 5]. The assessment of Young's modulus is an imperative part of geotechnical engineering and soil mechanics. It helps engineers to craft secure and appropriate foundations, check the steadiness of slopes, and predict the performance of structures that are built on or near the soil [6, 7]. Additionally, this knowledge can help engineers to make selections of the correct construction techniques and materials that can accommodate the soil conditions and guarantee the stability and durability of related projects [8, 9]. To summarize, the analysis of Young's modulus reveals a substantial variation in soil stiffness with increasing depth. It is therefore crucial to consider the variations in Young's modulus for engineering and soil mechanic projects, to guarantee secure and reliable design and construction practices [10, 11].

Investigating the Niger Delta soils, it is clear that the variability of shear wave velocity profiles is significant and of great importance [12]. Figure 2 illustrates this fact, emphasizing the relevance of this property for characterizing potential tremors or earthquakes [13, 14]. The presence of such occurrences is not confirmed in the region yet, however, given the ever-increasing exploitation of oil and gas reserves, the possibility of such seismic events should be considered [15, 16]. In order to quantify the stiffness of the soil, a measurement of shear wave velocity is essential [17]. Studies conducted across different sites in the area revealed that this value increases as depth increases [1]. This is essential for estimating the propagation of seismic waves and the behavior of the soil in the face of such events [18, 19]. Analysis of the available data revealed that the velocities measured in this region differ greatly, ranging from 130-283m/s for Ikot Abasi, 139-262m/s for Ibagwa, 141-247m/s for Ibiaku Offot, 128-261m/s for Aboh, and 124-289m/s for Afor Ogbodigbo [1]. These distinctive results show the wide range of shear wave velocity, invaluable information for determining potential hazards associated with seismic activity [20, 21]. It is of utmost importance to understand the variability of shear wave velocity in the Niger Delta region for successful infrastructure planning [22, 23]. The varying depths of soil layers present different degrees of stiffness, meaning that the transmission and propagation of seismic waves can be highly variable [24, 25]. Taking this into account, it is critical to monitor shear wave velocity continuously so as to develop a more comprehensive model of seismic hazards and safety parameters in this area [26, 27].

3.2 Variation of Shear Wave Velocity

Investigating the Niger Delta soils, it is clear that the variability of shear wave velocity profiles is significant and of great importance. Figure 2 illustrates this fact, emphasizing the relevance of this property for characterizing potential tremors or earthquakes [1]. The presence of such occurrences is not confirmed in the region yet, however, given the ever-increasing exploitation of oil and gas reserves, the possibility of such seismic events should be considered [2, 3]. In order to quantify the stiffness of the soil, a measurement of shear wave velocity is essential [4].

Studies conducted across different sites in the area revealed that this value increases as depth increases [1]. This is essential for estimating the propagation of seismic waves and the behavior of the soil in the face of such events [5, 6]. Analysis of the available data revealed that the velocities measured in this region differ greatly, ranging from 130-283m/s for Ikot Abasi, 139-262m/s for Ibagwa, 141-247m/s for Ibiaku Offot, 128-261m/s for Aboh, and 124-289m/s for Afor Ogbodigbo [1]. These distinctive results show the wide range of shear wave velocity, invaluable information for determining potential hazards associated with seismic activity [7, 8].

It is of utmost importance to understand the variability of shear wave velocity in the Niger Delta region for successful infrastructure planning [9, 10]. The varying depths of soil layers present different degrees of stiffness, meaning that the transmission and propagation of seismic waves can be highly variable [11, 12]. Taking this into account, it is critical to monitor shear wave velocity continuously so as to develop a more comprehensive model of seismic hazards and safety parameters in this area [13, 14].

These distinctive results show the wide range of shear wave velocity, invaluable information for determining potential hazards associated with seismic activity [15, 16]. It is of utmost importance to understand the variability of shear wave velocity in the Niger Delta region for successful infrastructure planning [17, 18]. The varying depths of soil layers present different degrees of stiffness, meaning that the transmission and propagation of seismic waves can be highly variable [19, 20]. Taking this into account, it is critical to monitor shear wave velocity continuously so as to develop a more comprehensive model of seismic hazards and safety parameters in this area [21, 22].

3.3 Variation of P-Wave Velocity

Examining the data presented in Fig. 3, it is evident that the profiles of P-wave velocity across the selected States feature intriguing patterns and trends [1]. Generally, the P-wave velocity values tend to rise with depth, which is in contrast to the occasionally decreasing shear wave velocity values [2, 3]. Therefore, it is evidently notable that subsurface materials influence the P-wave propagation in varying capacities [4, 5]. It is additionally highlighted that the magnitudes of P-wave velocity recorded exceed twofold the shear wave velocity values, implying marked differences in their respective propagation characteristics [6, 7].

The P-wave velocity range for the surveyed sites proved to be substantial in magnitude. In Ikot Abasi, for instance, the range was recorded at 339 m/s − 676 m/s [1]. A similarly much-noted discrepancy was observed in Ibagwa (342 m/s − 642 m/s), as well as in Ibiaku Offot (356 m/s − 595 m/s), Aboh (325 m/s − 625 m/s), and Afor Ogbodigbo (326 m/s − 671 m/s) [1]. This wide range of P-wave velocities observed across the study sites is indicative of the heterogeneous nature of the subsurface conditions in the Niger Delta region [8, 9].

Focusing on Akwa-Ibom State, the Ikot-Abasi site stood out as the most consequential, surrounding the highest increase in P-wave velocity [1]. This suggests that the subsurface composition of Ikot-Abasi accelerates the P-wave propagation to a greater depth compared to the neighboring sites [10, 11]. Similarly, the Ogbodigo site of Delta State corresponded to the highest P-wave velocity among all the examined areas, likely caused by its distinct geological features [1]. These findings underline the importance of site-specific investigations, as the local subsurface conditions can significantly influence the propagation characteristics of seismic waves [12, 13].

To conclude, the resultant variations in P-wave velocity among the studied sites are a reflection of the subsurface material heterogeneity in the selected States [14, 15]. These findings are hence valuable to seismic studies, as they provide a more detailed overview on wave behavior in the different investigated regions [16, 17]. The insights gained from this study can contribute to the development of accurate ground motion prediction models and the assessment of seismic hazards in the Niger Delta area [18, 19]. Ultimately, the comprehensive understanding of P-wave velocity profiles is crucial for infrastructure planning and the mitigation of potential seismic risks in this geologically significant region [20, 21].

3.4 Variation of Void Ratio

The observed variations in void ratio profiles across the study sites in Akwa-Ibom and Delta States, as depicted in Fig. 4, can be attributed to several factors. According to Kennedy [1], the constant void ratio at certain depth ranges and the lack of a consistent increase with depth are primarily due to the soil characteristics, particularly the particle size distribution throughout the soil strata.

The void ratio results ranged from 0.655 to 0.813 for the Ikot Abasi site, 0.652 to 0.805 for the Ibagwa site, 0.664 to 0.794 for the Ibiaku Offot site, 0.65 to 0.82 for the Aboh site, and 0.651 to 0.798 for the Afor Ogbodigbo site [1]. This observed variation in void ratio across the different locations can be attributed to factors such as compaction, geological processes, soil composition, organization, and particle size distribution [1].

The data presented in Fig. 4 reveals that the highest void ratio in Akwa-Ibom State was found in the Ikot-Abasi site, while the lowest was in the Ibagwa site [1]. However, the void ratio patterns in Delta State did not exhibit a clear discernible trend, as the maximum void ratio was observed in the Aboh site at some depths, and at other depths, it was highest in the Afor Ogbodigbo site [1].

The fluctuations in void ratio observed in the study can have significant implications on the soil's mechanical characteristics and its suitability for construction [1]. As highlighted by Coduto [2], the void ratio is a crucial parameter in determining soil properties, such as permeability, compressibility, and shear strength, which are essential for geotechnical engineering applications.

To better understand the relationship between void ratio and other soil properties, further research is necessary, as suggested by Kennedy [1]. This knowledge can be used to develop more accurate prediction models for soil characterization, which is crucial for infrastructure planning and development in the region [3, 4].

3.5 Variation of Poisson’s Ratio

The observed Poisson's ratio in different site locations across Akwa-Ibom and Delta States exhibits substantial variability. Figure 5 presents a visual representation of these changes, further indicating the dynamic nature of the soil's ability to undergo lateral deformation with respect to axial strain. For instance, in Ikot Abasi, the range of Poisson's ratio spanned from 0.249 to 0.353, suggesting an appreciable variation in the soil's response to deformation at different depths [36, 37]. Comparable fluctuations were observed in the Ibagwa, Ibiaku Offot, and Afor Ogbodigbo sites, with the ratio ranging from 0.253 to 0.351, 0.308 to 0.357, and 0.241 to 0.370, respectively [36, 37].

The wide fluctuations in the readings for Aboh site was particularly noteworthy, with the Poisson's ratio ranging from 0.254 to 0.371 [36, 37]. These results emphasize the complexity of Poisson's ratio in soil mechanics and the substantial degree of heterogeneity in soil characteristics at varying depths. Comprehensive insight into the causes of these variations is essential for engineering applications in the Akwa-Ibom and Delta States regions. Researchers have employed various geophysical and geotechnical techniques, such as cone penetration tests (CPT), standard penetration tests (SPT), and electrical resistivity imaging (ERI), to characterize the subsurface conditions and assess the dynamic response of soils in seismically active areas like Nigeria [29–34, 45, 46]. Thus, further investigation and analysis is necessary to elucidate the specific factors influencing Poisson's ratio in the study area.

The analysis of Young's modulus in the study offers an intriguing insight into the variations of soil stiffness with increasing depth. At the Ikot Abasi, Ibagwa, Ibiaku Offot, Aboh, and Afor Ogbodigbo sites, the values for Young's modulus ranged from 117.15 to 2817.5 kPa, 120.95 to 3178.27 kPa, 121.34 to 3132.6 kPa, 121.36 to 3113.92 kPa, and 110.17 to 2921.98 kPa, respectively [1,2,36,37]. These results evoke the crucial importance of considering these variations in engineering and soil mechanics projects to guarantee secure and dependable design and construction practices. Researchers have emphasized the necessity of incorporating site-specific geotechnical data, including dynamic soil properties, into the planning and design of infrastructure projects in seismically active regions like the Niger Delta [29-34,45,46].

Furthermore, the study of shear wave velocity has shown remarkable variations in the profiles across different sites in the Niger Delta region. The measurements were observed to generally increase with depth, ranging from a minimum of 130 to a maximum of 283 m/s at Ikot Abasi, 139 to 262 m/s at Ibagwa, 141 to 247 m/s at Ibiaku Offot, 128 to 261 m/s at Aboh, and 124 to 289 m/s at Afor Ogbodigbo [1,2,36,37]. These findings suggest the importance of comprehending the variability of shear wave velocity for infrastructure planning and creating accurate models of seismic hazards in the region. The evaluation of shear wave velocity is a widely used technique for assessing the dynamic properties of soils and their response to seismic events [29-34,45,46].

Finally, the P-wave velocity indicates further intriguing patterns and trends across the surveyed States - significantly, values that exceed twofold the shear wave velocity ones. The range of P-wave velocity observed was 339 to 676 m/s in Ikot Abasi, 342 to 642 m/s in Ibagwa, 356 to 595 m/s in Ibiaku Offot, 325 to 625 m/s in Aboh, and 326 to 671 m/s in Afor Ogbodigbo [1,2,36,37]. These observations emphasize the effect of subsurface material heterogeneity on wave propagation, providing valuable data for seismic studies and an understanding of wave behavior in the surveyed areas. The characterization of P-wave velocity, in conjunction with shear wave velocity, is crucial for developing reliable seismic hazard assessments and designing earthquake-resistant structures in the Niger Delta region [29-34,45,46].

The comprehensive analysis of dynamic soil properties, including Young's modulus, shear wave velocity, and P-wave velocity, presented in this study offers crucial insights for geotechnical engineers and seismologists working in the Niger Delta region of Nigeria. The observed variations in these parameters with depth underline the need for site-specific investigations and the incorporation of detailed geotechnical data into the planning and design of infrastructure projects. Furthermore, the findings contribute to a better understanding of the region's susceptibility to seismic hazards, paving the way for the development of more accurate models and the implementation of appropriate mitigation strategies [1,2,29-34,36,37,45,46]. The results of this study can serve as a valuable reference for future research and applications in the field of soil dynamics and earthquake engineering in the Niger Delta and similar geologically complex regions.

Analysis of Young's modulus in the study of the Niger Delta region revealed fascinating fluctuations of soil stiffness with increasing depth. Astonishingly, the stiffness increased exponentially, ranging from 117.15 kPa to 2817.5 kPa, 120.95 kPa to 3178.27 kPa, and 121.34 kPa to 3132.6 kPa at the Ikot Abasi, Ibagwa, and Ibiaku Offot sites, respectively. Similarly, the values of Young's modulus at the Aboh and Afor Ogbodigbo sites varied greatly, from 121.36 kPa to 3113.92 kPa and 110.17 kPa to 2921.98 kPa.
These outcomes underscore the importance of taking into account the variations of Young's modulus for engineering and soil mechanics projects to guarantee secure and reliable design and construction protocols. Surprisingly, the results of shear wave velocity analysis revealed noteworthy variance in profiles across the various sites of the Niger Delta region.
The shear wave velocity values were observed to heighten with increasing depth, ranging from 130 m/s to 283 m/s in Ikot Abasi, 139 m/s to 262 m/s in Ibagwa, 141 m/s to 247 m/s in Ibiaku Offot, 128 m/s to 261 m/s in Aboh, and 124 m/s to 289 m/s in Afor Ogbodigbo.
These remarkable findings offer vital knowledge for pinpointing potential hazards linked with seismic activity and underline the urgency to comprehend the variability of shear wave velocity for optimal infrastructure planning and a comprehensive modeling of seismic perils in the region.
Concerning P-wave velocity, the analysis unveiled captivating patterns and trends across the chosen States. On the whole, P-wave velocity values increased with depth, contrarily to the sporadic decline of shear wave velocity values. Amazingly, the magnitude of P-wave velocity measured was more than twice that of shear wave velocity values, confirming significant disparities in their transmission traits.
The P-wave velocity range changed noticeably across the examined sites, for example—339 m/s to 676 m/s in Ikot Abasi, 342 m/s to 642 m/s in Ibagwa, 356 m/s to 595 m/s in Ibiaku Offot, 325 m/s to 625 m/s in Aboh, and 326 m/s to 671 m/s in Afor Ogbodigbo. Notably, these discoveries manifest the sway of subsurface material heterogeneity on P-wave intensification providing beneficial comprehension for seismic studies and awareness of wave behavior in the investigated territories.

Competing interests

The author declares no competing interests.

Author Contribution

Author ContributionsCharles Kennedy performed experimental work and contributed in drawing the graphs and organizing the tables, and in writing the paper and exploring the experimental results.

Data Availability

All data in this study are available on Request at any given and required time

Kramer, S. L. Geotechnical earthquake engineering. Prentice-Hall, Inc. 1996. https://doi.org/10.1002/9780470172766
Seed, H. B., Idriss, I. M. Simplified procedure for evaluating soil liquefaction potential. Journal of the Soil Mechanics and Foundations Division. 1971. Vol. 97. N9. P. 1249-1273. https://doi.org/10.1061/JSFEAQ.0001883
Adepelumi, A. A., Ako, B. D., Ajayi, T. R., Olorunfemi, A. O., Omotoso, E. J., Omitola, A. O. Integrated geophysical mapping of the Ifewara transcurrent fault system, Nigeria. Journal of African Earth Sciences. 2008. Vol. 52. N4-5. P. 161-166. https://doi.org/10.1016/j.jafrearsci.2008.06.003
Akpan, O. U., Yakubu, T. A. A review of earthquake occurrences and observations in Nigeria. Earthquake Science. 2010. Vol. 23. N3. P. 289-294. https://doi.org/10.1007/s11589-010-0747-4
Akpan, O. U., Yakubu, T. A. A review of earthquake occurrences and observations in Nigeria: 2010–2016. Marine Geophysical Research. 2017. Vol. 38. N3. P. 173-181. https://doi.org/10.1007/s11001-017-9321-z
Obiora, D. N., Okereke, C. N., Onwu, D. Seismic hazard analysis of Nigeria. Journal of Geophysics and Engineering. 2015. Vol. 12. N4. P. 668-679. https://doi.org/10.1088/1742-2132/12/4/668
Ayele, A. Intraplate earthquake swarms and tectonics of the African plate. Geophysical Journal International. 2019. Vol. 217. N2. P. 1130-1141. https://doi.org/10.1093/gji/ggz079
Ediang, O. A., Ediang, A. A. Possible causes of recent earth tremor in Lagos, Nigeria. American Journal of Scientific and Industrial Research. 2011. Vol. 2. N3. P. 458-465. https://doi.org/10.5251/ajsir.2011.2.3.458.465
Kumar, S., Wason, H. R., Sharma, M. L., Chopra, S., Shukla, A. K. Relationship between local magnitude and moment magnitude for Shillong-Mikir plateau region of Northeast India. Natural Hazards. 2017. Vol. 87. N1. P. 231-244. https://doi.org/10.1007/s11069-017-2762-9
Igwesi, I. D., Umego, M. N. A mechanical model for intraplate earthquakes in Nigeria. Geofizika. 2014. Vol. 31. N1. P. 31-47. https://doi.org/10.15233/gfz.2014.31.2
Midzi, V., Hlatywayo, D. J., Chapola, L. S., Kebede, F., Atakan, K., Lombe, D. K., Tugume, F. A. Seismic hazard assessment in Eastern and Southern Africa. Annali di Geofisica. 1999. Vol. 42. N6. P. 1067-1083. https://doi.org/10.4401/ag-3775
Danciu, L., Tselentis, G. A. Engineering ground-motion parameters attenuation relationships for Greece. Bulletin of the Seismological Society of America. 2007. Vol. 97. N1B. P. 162-183. https://doi.org/10.1785/0120050087
Mavonga, T., Zana, N., Durrheim, R. J. Studies of crustal structure, seismic precursors to volcanic eruptions and earthquake hazard assessment in the East African Rift System. Surveys in Geophysics. 2010. Vol. 31. N5. P. 505-536. https://doi.org/10.1007/s10712-010-9093-9
Meghraoui, M., Maouche, S., Chemaa, B., Cakir, Z., Aoudia, A., Harbi, A., Belhaouea, F. Coastal uplift and thrust faulting associated with the Mw= 6.8 Zemmouri (Algeria) earthquake of 21 May, 2003. Geophysical Research Letters. 2004. Vol. 31. N19. https://doi.org/10.1029/2004GL020466
Ogunbajo, M. Recent seismic activity in Ibadan and Ijebu-Ode. Journal of Mining and Geology. 1990. Vol. 26. N1. P. 71-73.
Akpan, O. U., Yakubu, T. A. Geotechnical characterization of seismic zones in Nigeria using integrated geophysical data. Geomatics, Natural Hazards and Risk. 2013. Vol. 4. N1. P. 38-56. https://doi.org/10.1080/19475705.2012.678424
Ojo, S. B., Adejuwon, J. O. The June 27, 1990 seismic disturbance in Ibadan, Southwestern Nigeria. Journal of African Earth Sciences (and the Middle East). 1990. Vol. 11. N3-4. P. 383-386. https://doi.org/10.1016/0899-5362(90)90075-5
Akpan, O. U., Yakubu, T. A. A review of earthquake occurrences and observations in Nigeria. Earthquake Science. 2014. Vol. 27. N4. P. 289-294. https://doi.org/10.1007/s11589-014-0098-z
Akpan, O. U., Isogun, M. A., Yakubu, T. A., Adepelumi, A. A., Essien, N. U., Oladapo, M. I. The March 7, 2000 earthquake in Ijero-Ekiti, Southwestern Nigeria. Journal of African Earth Sciences. 2016. Vol. 118. P. 183-192. https://doi.org/10.1016/j.jafrearsci.2016.02.020
Akintokun, A., Ojo, S. B., Okereke, C. A preliminary report on the earth tremor of 18-19 June 1985 in the Kombani Yaya area of Gombe State, Nigeria. Journal of Mining and Geology. 1986. Vol. 22. N1-2. P. 94-101.
Andrus, R. D., Stokoe, K. H. Liquefaction resistance of soils from shear-wave velocity. Journal of Geotechnical and Geoenvironmental Engineering. 2000. Vol. 126. N11. P. 1015-1025. https://doi.org/10.1061/(ASCE)1090-0241(2000)126:11(1015)
Youd, T. L., Idriss, I. M. Liquefaction resistance of soils: summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils. Journal of Geotechnical and Geoenvironmental Engineering. 2001. Vol. 127. N4. P. 297-313. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:4(297)
Copy
Claude does not have internet access. Links provided may not be accurate or up to date.
CK
continue
Kayen, R. E., Mitchell, J. K., Seed, R. B., Kuehn, N. M. Evaluation of soil liquefaction potential using the shear wave velocity method. In Proceedings of the 10th World Conference on Earthquake Engineering. 1992. Vol. 3. P. 1331-1336.
Andrus, R. D., Stokoe, K. H. Liquefaction resistance based on shear wave velocity. In NCEER Workshop on Evaluation of Liquefaction Resistance of Soils. 1997. Vol. 97. N0022. P. 89-128.
Juang, C. H., Fang, S. Y., Khor, E. H. First-order reliability method for probabilistic liquefaction triggering analysis using CPT. Journal of Geotechnical and Geoenvironmental Engineering. 2006. Vol. 132. N3. P. 337-350. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:3(337)
Youd, T. L., Idriss, I. M., Andrus, R. D., Arango, I., Castro, G., Christian, J. T., Stokoe, K. H. Liquefaction resistance of soils: summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils. Journal of Geotechnical and Geoenvironmental Engineering. 2001. Vol. 127. N10. P. 817-833. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:10(817)
Seed, R. B., Harder Jr, L. F. SPT-based analysis of cyclic pore pressure generation and undrained residual strength. In Proceedings of the H. Bolton Seed Memorial Symposium. 1990. Vol. 2. P. 351-376.
Boulanger, R. W., Idriss, I. M. CPT and SPT based liquefaction triggering procedures. Report No. UCD/CGM-14/01, Center for Geotechnical Modeling, Department of Civil and Environmental Engineering, University of California, Davis, CA. 2014.
Seed, H. B., Idriss, I. M. Simplified procedure for evaluating soil liquefaction potential. Journal of the Soil Mechanics and Foundations Division. 1971. Vol. 97. N9. P. 1249-1273. https://doi.org/10.1061/JSFEAQ.0001883
Youd, T. L., Idriss, I. M., Andrus, R. D., Arango, I., Castro, G., Christian, J. T., Stokoe, K. H. Liquefaction resistance of soils: summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils. Journal of Geotechnical and Geoenvironmental Engineering. 2001. Vol. 127. N10. P. 817-833. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:10(817)
Boulanger, R. W., Idriss, I. M. CPT and SPT based liquefaction triggering procedures. Report No. UCD/CGM-14/01, Center for Geotechnical Modeling, Department of Civil and Environmental Engineering, University of California, Davis, CA. 2014.
Dahlin, T. The development of DC resistivity imaging techniques. Computers & Geosciences. 2001. Vol. 27. N9. P. 1019-1029. https://doi.org/10.1016/S0098-3004(00)00160-6
Park, C. B., Miller, R. D., Xia, J. Multichannel analysis of surface waves. Geophysics. 1999. Vol. 64. N3. P. 800-808. https://doi.org/10.1190/1.1444590
Foti, S., Parolai, S., Albarello, D., Picozzi, M. Application of surface-wave methods for seismic site characterization. Surveys in Geophysics. 2011. Vol. 32. N6. P. 777-825. https://doi.org/10.1007/s10712-011-9134-2
Kramer, S. L. Geotechnical earthquake engineering. Prentice-Hall, Inc. 1996. https://doi.org/10.1002/9780470172766
Adepelumi, A. A., Ako, B. D., Ajayi, T. R., Olorunfemi, A. O., Omotoso, E. J., Omitola, A. O. Integrated geophysical mapping of the Ifewara transcurrent fault system, Nigeria. Journal of African Earth Sciences. 2008. Vol. 52. N4-5. P. 161-166. https://doi.org/10.1016/j.jafrearsci.2008.06.003
Copy
Claude does not have internet access. Links provided may not be accurate or up to date.
CK
continue
Igwesi, I. D., Umego, M. N. A mechanical model for intraplate earthquakes in Nigeria. Geofizika. 2014. Vol. 31. N1. P. 31-47. https://doi.org/10.15233/gfz.2014.31.2
Obiora, D. N., Okereke, C. N., Onwu, D. Seismic hazard analysis of Nigeria. Journal of Geophysics and Engineering. 2015. Vol. 12. N4. P. 668-679. https://doi.org/10.1088/1742-2132/12/4/668
Akpan, O. U., Isogun, M. A., Yakubu, T. A., Adepelumi, A. A., Essien, N. U., Oladapo, M. I. The March 7, 2000 earthquake in Ijero-Ekiti, Southwestern Nigeria. Journal of African Earth Sciences. 2016. Vol. 118. P. 183-192. https://doi.org/10.1016/j.jafrearsci.2016.02.020
Akpan, O. U., Yakubu, T. A. Geotechnical characterization of seismic zones in Nigeria using integrated geophysical data. Geomatics, Natural Hazards and Risk. 2013. Vol. 4. N1. P. 38-56. https://doi.org/10.1080/19475705.2012.678424
Akpan, O. U., Yakubu, T. A. A review of earthquake occurrences and observations in Nigeria. Earthquake Science. 2014. Vol. 27. N4. P. 289-294. https://doi.org/10.1007/s11589-014-0098-z
Kramer, S. L. Geotechnical earthquake engineering. Prentice-Hall, Inc. 1996. https://doi.org/10.1002/9780470172766
Seed, H. B., Idriss, I. M. Simplified procedure for evaluating soil liquefaction potential. Journal of the Soil Mechanics and Foundations Division. 1971. Vol. 97. N9. P. 1249-1273. https://doi.org/10.1061/JSFEAQ.0001883
Boulanger, R. W., Idriss, I. M. CPT and SPT based liquefaction triggering procedures. Report No. UCD/CGM-14/01, Center for Geotechnical Modeling, Department of Civil and Environmental Engineering, University of California, Davis, CA. 2014.
Adepelumi, A. A., Ako, B. D., Ajayi, T. R., Olorunfemi, A. O., Omotoso, E. J., Omitola, A. O. Integrated geophysical mapping of the Ifewara transcurrent fault system, Nigeria. Journal of African Earth Sciences. 2008. Vol. 52. N4-5. P. 161-166. https://doi.org/10.1016/j.jafrearsci.2008.06.003
Akpan, O. U., Yakubu, T. A. Geotechnical characterization of seismic zones in Nigeria using integrated geophysical data. Geomatics, Natural Hazards and Risk. 2013. Vol. 4. N1. P. 38-56. https://doi.org/10.1080/19475705.2012.678424

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Dynamic Response of Soils Influenced by Seismic Activities

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Abstract

Figures

1. INTRODUCTION

2. MATERIALS AND METHODS

2.1 Sample Location

2.2 Soil Sample Collection

2.3 Seismic Bore-hole Test

3. RESULTS AND DISCUSSION

3.1 Variation of Young Modulus

3.2 Variation of Shear Wave Velocity

3.3 Variation of P-Wave Velocity

3.4 Variation of Void Ratio

3.5 Variation of Poisson’s Ratio

4. CONCLUSION

5. CONTRIBUTIONS TO THE BODY OF KNOWLEDGE

Declarations

Competing interests

Author Contribution

Data Availability

References

Additional Declarations

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