Hard Soil Research Articles

Seismic Behavior of RC Multistorey Building Frame Structure with Different Plan Configuration

Today’s world facing some of the major problems causing by the nature. One of the major natural disasters is the Earthquake. We never know the Direction of the attack and magnitude of the Earthquake, so it will be the challenge the science and Technology. Past few years’ research done on the various issues of Earthquake. Now a Days people live in Multi-Story Buildings such case when Earthquake knockout the populated areas it will be cause massive loss of Damage. Hence Earthquake analysis get importance to Analysis the structure safe against the collapse and design the structure to safe against earthquake occur during the life time of the structure. In this study model a G+11 Structure with square plan configuration in Staad Pro and Analysis the Earthquake analysis of the Structure in seismic city Jabalpur which is located in seismic region III with Soft, Hard and Medium soil with different seismic and structural parameters are used as per Indian Standard code. The analysis is done by using STAAD Pro V8i software by Linear Static Analysis and compared the analysis of RC multistory building framed structure in the term of Maximum Bending MomentStory wise Displacement

Numerically evaluate axial force variations of jointed precast piles during construction

The axial force variation along the length of the jointed precast pile is influenced by the hard soil layer properties during construction. For this purpose, this research proposes an innovative concept of spring model of jointed precast pile to evaluate the axial force variations along the length to consider some variable parameters (i.e. soil elastic moduli, soil Poisson’s ratios, hammer loads, compressive strengths and sizes of precast piles). The linear elastic analysis is performed by using finite element-based software ETABS v. 18.1.1 to consider 3-nodded line element of the jointed precast pile. Variable parameters are influenced to increase the normalized axial force of the jointed precast pile because of increasing stiffness, self-weight, etc. The difference in result of 6.84% may indicate a good agreement with the verification of the numerical analysis. The rates of the normalized axial force increments for variable soil elastic moduli, soil Poisson’s ratios, and precast pile sizes are found to be (1 to 2) %, (1.25 to 1.75) %, and (27 to 36) %, respectively. In addition, the maximum axial force increment rate is found to be 0.47% for precast pile sizes of 400 × 400 and 450 × 450 mm.

Root Penetration Is Associated with Root Diameter and Root Growth Rate in Tropical Forage Grasses

Soil compaction impedes root exploration by plants, which limits access to nutrients and water, ultimately compromising survival. The capability of roots to penetrate hard soils is therefore advantageous. While root penetration has been studied in various annual crops, the relationships between root growth and root penetration are poorly understood in tropical perennial grasses. This study aimed to compare root penetration capability in 10 tropical perennial forage grasses and identify relationships between root penetration, root diameter and vertical root growth. Root penetration of each species, namely Urochloa (syn. Brachiaria) brizantha cv. Mekong Briz, U. decumbens cv. Basilisk, U. humidicola cv. Tully, U. hybrid cv. Mulato II, U. mosambicensis cv. Nixon, U. ruziziensis cv Kennedy, Panicum coloratum cv. Makarikariense, Megathyrsus maximus (syn. Panicum maximum) cv. Tanzânia, Paspalum scrobiculatum (syn. Paspalum coloratum) cv. BA96 10 and Setaria sphacelata cv Solendar, was evaluated using wax layers of varying resistances, created from a mixture of 40% (1.39 MPa) and 60% (2.12 MPa) paraffin wax, combined with petroleum jelly. Reference root sizes were determined for the grass species by measuring root diameter and root lengths of seedlings grown in growth pouches. Vertical root growth rate for each species was measured in grasses grown in 120 cm deep rhizotrons. Species with greater root penetration at both resistances had significantly higher shoot growth rates (r = 0.65 at 40% wax and 0.66 at 60% wax) and greater root diameters (r = 0.67 at 40% wax and 0.68 at 60% wax). Root penetration was significantly higher in species with greater vertical root growth rate only in the 60% wax treatment (r = 0.82). Root penetration at higher resistance was correlated with the root diameter and rapid vertical root growth of the species. This may indicate a contribution of these traits to root penetration ability. The combination of greater root diameter and root vertical growth rate, as observed in M. maximus, may assist in the identification of perennial forage grasses suitable for agroecosystems challenged by soil compaction and rapidly drying soil surface.

Pushover Analysis of a Reinforced Cement Concrete (RCC) Structure Incorporating Fibre-Reinforced Polymers to Address Vertical Irregularities

India has had four of the world's most destructive earthquakes in the past ten years, and our country is often rocked by earthquakes of low to moderate intensity. Since many buildings were severely damaged or collapsed, it has sparked debate whether framed constructions are sufficiently sturdy to withstand significant vibrations. As a result, the strength or ability of existing reinforced concrete structures to withstand seismic loads can be evaluated. The performance level of earthquake-prone buildings is evaluated using a performance-based design. One seismic technique for assessing a building's performance level is push-over analysis. It is possible to determine whether damage occurs at the member or structure level using pushover analysis. The study employs pushover analysis by Applied Technology Council (ATC) – 4), a seismic assessment technique, to evaluate the ability of 20-story buildings in seismic Zone III (with hard soil characteristics) to resist earthquake-induced forces. The primary objective was to assess the performance of structures reinforced with different fiber-reinforced polymer (FRP) materials, including aramid, glass, and carbon fibers, known for their high flexibility and strength in seismically active regions. To determine the best fiber-reinforced polymer configuration, the study considers the following parameters: pushover curve, target displacement, story shear, time period, maximum story displacement, and story drift based on pushover analysis independently. Through the pushover analysis method, the research discovers that FRP wrapping can significantly improve the seismic performance of reinforced concrete buildings. The findings aim to improve building design practices by recommending fiber-reinforced polymer configurations for better earthquake resistance, ensuring that future constructions are better equipped to handle seismic activity.

Intraspecific variation in root system structure in a Pinus thunbergii stand grown in a gravelly spit coast.

ABSTRACT Root systems of Pinus thunbergii planted in coastal forests exhibit high phenotypic plasticity under edaphic conditions. The objectives of this study were as follows: 1) to determine intraspecific variation in root system traits, maximum root depth and length of horizontal roots of P. thunbergii in a gravelly spit within a stand by excavation of entire root systems, and root system structure modelling from photographs; and 2) to determine whether the root system traits can be inferred from aboveground traits. The P. thunbergii trees grew twisting roots through the hard soil layer of sand and gravel and exhibited variation in root systems; most individuals had inherent tap root systems, but one had a two-tiered thick horizontal root system with a thinner tap root. Although the maximum length of the horizontal root had no relationship with the aboveground traits, the maximum root depth of P. thunbergii was significantly related to tree height. This suggests that tree height can be a predictive indicator of root depth, which is valuable for the rehabilitation of disaster-resistant coastal forests. Both surface and solid models of root system were produced using structure-from-motion with a multi-view stereophotogrammetry method, which enabled continuous estimation of the sum of the root cross-sectional area at any depth in the depth direction. The new method of reconstructing root system models was effective for post-analysis of traits after excavation. We concluded that intraspecific variations in the root system traits of P. thunbergii were observed even at the stand level on a gravelly spit coast.

Did Crop Domestication Change the Fitness Landscape of Root Response to Soil Mechanical Impedance? An in-silico Analysis.

Root axes with greater penetration ability are often considered to be beneficial in hard soils. We hypothesized that maize root phenotypes with greater plasticity (meaning reduced elongation in response to mechanical impedance, i.e. a 'stop signal') have fitness advantages over phenotypes with reduced plasticity (i.e. unimpeded root elongation) in native (virgin, uncultivated) soils, by reallocating root foraging to softer, presumably wetter, soil domains, and that the value of the stop signal reduced with soil cultivation and crop domestication. We used OpenSimRoot to simulate native and cultivated soils and evaluated maize root phenotypes with varying axial and lateral root penetration ability in water, nitrogen, and impedance regimes associated with Neolithic agriculture. The stop signal was advantageous in native soils but was less beneficial in cultivated, irrigated soils. Reduced root foraging in hard, dry topsoil enabled root growth in deeper domains where water is available, resulting in an improved balance of resource expenditure and acquisition. The value of the stop signal declined during crop domestication with the advent of irrigation, which increased water availability in the topsoil. Soil cultivation reduced N availability, while irrigation increased N leaching, resulting in a shift in the fitness landscape, with greater lateral root length (i.e. reduced plasticity) being advantageous by colocalizing root foraging with N availability. The importance of the stop signal is evident in modern high-input systems in which drought is a limiting factor. Our results support the hypotheses that the reduction of lateral root growth by mechanical impedance is adaptive in native soil, but became less adaptive with soil cultivation and irrigation associated with Neolithic agriculture.

The Dynamic Soil–Foundation–Structure Interaction Problem in the Time Domain Using a Discrete Element Model

This study investigates the influence of the soil–structure interaction (SSI) on the seismic performance of structures, focusing on the effects of foundation size, soil type, and superstructure height. While the importance of SSI is well recognized, its impact on structural behavior under seismic loads remains uncertain, particularly in terms of whether it reduces or amplifies structural demands. A simplified dynamic model, incorporating both the mechanical behavior of the soil and structural responses, is developed and validated to analyze these effects. Using a discrete element approach and the 1940 El Centro earthquake for validation, the study quantitatively compares the response of soil-interacting structures to those with fixed bases. The numerical results show that larger foundation blocks (20 m × 20 m and 30 m × 30 m) increase the seismic response values across all soil types, causing the structure to behave more like a fixed-base system. In contrast, reducing the foundation size to 10 m × 10 m increases the flexibility of structures, particularly buildings built on soft soils, which affects the displacement and acceleration response spectra. Softer soils also increase natural vibration periods and extend the plateau region in regard to spectral acceleration. This study further finds that foundation thickness has a minimal impact on spectral displacement, but structures on soft soils show more than a 15% reduction in spectral displacement (SD) compared to those on hard soils, indicating a dampening effect. Additionally, increasing the building height from 7 to 21 m results in a more than 20% decrease in SD for superstructures with natural vibration periods exceeding 2.4 s, while taller buildings with longer natural vibration periods exhibit opposite trends. Structures built on soft soils experience larger foundation-level displacements, absorbing more seismic energy and reducing earthquake accelerations, which mitigates structural damage. These results highlight the importance of considering SSI effects in seismic design scenarios to achieve more accurate performance predictions.

Global Sensitivity Analysis of the Fundamental Frequency of Jacket-Supported Offshore Wind Turbines Using Artificial Neural Networks

Determining the fundamental frequency of Offshore Wind Turbines (OWTs) is crucial to ensure the reliability and longevity of the structure. This study presents a global sensitivity analysis of the fundamental frequency of OWTs on jacket foundations. Monte Carlo sampling was employed to generate a diverse set of wind turbines, emplacements, and jacket designs, ensuring that the generated samples are realistic and yield relevant conclusions. The fundamental frequency and its partial derivatives were obtained via a previously developed ANN model. The relative sensitivities were computed to facilitate the comparison of their influence. The results demonstrate that wind turbine properties are the most relevant variables affecting the fundamental frequency, with a decrement in frequency caused by tower height and rotor-nacelle assembly mass, as well as an increment due to the section dimensions of the tower, particularly at its base. Soil properties have a significant effect on foundation stiffness for soft and light soils but can be neglected for hard and heavy soils. The diameter and thickness of the braces also show different relevance depending on their dimensions, producing rigid links between legs for greater sections. This study provides a measure of the variables influencing the fundamental frequency, facilitating a deeper comprehension of this phenomenon.

Assessment of Waterlogging and Mitigation Strategies for Alanda Micro Watershed Using Remote Sensing in Akola District of Vidarbha Region, India

The socio-economic progress of Vidarbha, where 89% of the land is used for rainfed farming, is significantly influenced by water resources. Unfortunately, waterlogging, driven by insufficient drainage and erratic weather conditions, poses serious challenges to agricultural productivity and soil health. The Alanda micro watershed in Barshitakli tehsil, Akola district, Vidarbha region of Maharashtra, features hard basaltic terrain and clay soils primarily used for agriculture. Poorly drained soils have caused waterlogging and salinization, highlighting the need for assessment of mitigation measures for the waterlogging to improve agricultural productivity and address climate change impacts. Waterlogging can be effectively identified through remote sensing techniques like NDWI, NDMI and NDVI, using high-resolution Landsat 8 imagery processed in ArcGIS 10.8. These methods facilitate the analysis and management of waterlogged areas, which is critical for improving agricultural output. The NDVI, NDWI and NDMI maps of the Alanda micro watershed highlight vegetation health, moisture levels and waterlogging potential, with the northern regions showing higher moisture and increased waterlogging risk. Mitigating waterlogging in the area requires the implementation of efficient drainage systems, soil improvement through organic matter and deep tillage and precise water management practices, including levelling fields to prevent water accumulation and using drought-resistant crops.

Analysis of Soil-Structure Interaction of Framed Structure

This study examines the soil-structure interaction (SSI) effects on the seismic behavior of G+7 and G+12 reinforced concrete buildings. Using finite element modelling in SAP2000, we assess key seismic parameters, including base shear, time period, lateral displacement, and footing settlement, across three soil types: soft, medium, and hard. This comparative analysis provides insights into how building height and soil flexibility influence structural stability, suggesting optimal design considerations for enhancing earthquake resilience. Key Words: Soil-Structure Interaction (SSI), Base Shear, Lateral Displacement, Seismic Analysis, G+7, G+12, SAP2000, Soft Soil, Medium Soil, Hard Soil.

Agustian, Daden Metode Pelaksanaan Pekerjaan Strauss Pile Proyek Gedung Kejaksaan Negeri Majalengka

Construction work is divided into different scopes of work, including structural, architectural, MEP and others. The structure is a means that functions to distribute live loads and dead loads into the ground. One part of the structure is the foundation which is a part of the building construction whose task is to place and transmit the load of the upper part of the building to the subgrade. The selection of the type of foundation structure is carried out by taking into account the condition of the soil, the limitations imposed by the structure above it, the limitations of the surrounding environment, the cost and time of carrying out the work. For example, the Majalengka District Attorney's building construction project uses a Strauss Pile foundation as the lower. Strauss foundation is a type of foundation that is used to carry loads when hard soil that has a strong bearing capacity is located very deep from the ground surface. In this project, the implementation of the Strauss Pile work refers to the provisions that must have the ASTM D 1143-81 standard regarding static compressive loading, using concrete quality K300 and reinforcing steel Ø ≥ 10 BJTD 40 and Ø≤ 10 BJTP 24. The work process starts from a series of works Preparation includes administrative equipment, land clearing and measurements, then carrying out work starting from drilling using a mini crane auger to casting, and finally testing as a technical report.

Impact of varying soil conditions on the design of tall building foundations

Above the past two decades, there has been a significant rise in the construction of tall structures over 150m in height, with an almost exponential development rate. Numerous similar structures have been built throughout the Middle East and Asia, and many more are proposed or now under development. Buildings over 300m in height are posing new engineering difficulties, especially in terms of structural and geotechnical design. Wind analysis is critical when it comes to big structures. Geotechnical engineers, in particular, are progressively abandoning empirical techniques in favor of state-of-the-art methods when designing foundations for super-tall structures. Numerous studies have investigated the structural behavior of tall structures with SSI by taking into account a variety of factors such as foundation type, soil conditions, lateral stresses, and the ratio of the flexural stiffness of the beam and column. Very few studies on the soil-structure interaction of tall structures in clayey soil conditions, especially in Indian seismic zones, have been conducted. In zone III, a G+18-story rectangular structure with a 3 m floor-to-floor height was assessed using the E-tabs software. The selected plan is rectangular in shape. The structure has been evaluated for static and dynamic wind and seismic forces. Structures have been developed for use in circumstances of hard, medium, and soft soil.

Stratigraphic Determination Based on Shear Wave Velocity for Earthquake Disaster Mitigation in Lebong District

Bengkulu Province, including North Bengkulu and Lebong, is located in the subduction zone of the Indo-Australian and Eurasian plates, which makes the region prone to earthquakes. This research focuses on earthquake disaster mitigation in the Lemeu area, Uram Jaya District, and Lebong Regency. It identifies areas prone to earthquake shaking based on Vs stratigraphy, Vs30 distribution, and soil site class. The Vs value was measured directly using the Multichannel Analysis of Surface Wave (MASW) method for three passes. Each track has four stations, so there are 12 data collection stations. The station point is the center point of a series of 24 geophones. Each geophone has a recording time of 512 ms and a sampling rate time of 125 ms to obtain 4096 data for each geophone. The measurement data was processed using WINMASW 5.0 professional software to produce a 1D profile. From the stratigraphic Vs, Vs30 is calculated and used to determine the site class, and then a distribution map is made. The results show that this area consists of site classes D, C and B. Medium soil with a value range of 175 ≤ Vs30 ≤ 350, hard soil with a value range of 350 ≤ Vs30 ≤ 750 and soft rock with a value range of 750 ≤ Vs30 ≤ 1500. Of the 12 measurement points, 2 locations have relatively shallow Vs30 values, namely at points 4 and 11. This location has Vs30 values ranging from 221 - 258 m/s, so around this point, there is likely a high potential for building damage in the event of an earthquake.

Physical obstacles in the substrate cause maize root growth trajectories to switch from vertical to oblique.

Hard pans, soil compaction, soil aggregation, and stones create physical barriers that can affect the development of a root system. Roots are known to exploit paths of least resistance to avoid such obstacles, but the mechanism through which this is achieved is not well understood. Here, we used a combination of 3D-printed substrates with a high-throughput live-imaging platform to study the responses of maize roots to a range of physical barriers. Using image analysis algorithms, we determined the properties of growth trajectories and identified how the presence of rigid circular obstacles affects the ability of a primary root to maintain its vertical trajectory. The results showed that the types of growth responses were limited, with both vertical and oblique trajectories being found to be stable and influenced by the size of the obstacles. When obstacles were of intermediate sizes, trajectories were unstable and changed in nature through time. We formalized the conditions required for root trajectory to change from vertical to oblique, linking the angle at which the root detaches from the obstacle to the root curvature due to gravitropism. Exploitation of paths of least resistance by a root might therefore be constrained by the ability of the root to curve and respond to gravitropic signals.

Pileslab Design in Pabaungan Hilir, Candi Laras Selatan District, Tapin Regency, South Kalimantan

The Pebaungan River is one of the river sections in Pabaungan Hilir, Candi Laras Selatan District, Tapin Regency, South Kalimantan. In this river, there is a retaining wall with a slope condition. This planning is carried out by collecting the necessary data, followed by an analysis of the characteristics of the study soil. The value of the safety factor for the current conditions is then calculated by simulating the stability of the slope using the geoslope. After that, the pileslab design is calculated by taking into account the loading, reinforcement, and foundation calculations. After the pileslab was fixed, the slope stability analysis modeling was again carried out to determine the safety factor.According to the analysis's findings, the study soil's characteristics for hard soil were at a depth of 40 meters, and the safety factor for slope stability under the current circumstances was 0.947, which was not safe. The pileslab calculation takes into account standard loading and reinforcement, as well as the foundation design using a 30x30 square pile and accounting for bearing capacity, the lateral force of the pile, and settlement. After that, modeling was carried out to get the value of the overall slope safety factor after the pileslab was installed, which came out to be 1.515. Keywords: Pileslab, slope stability, settlement, bearing capacity

Evaluasi Kapasitas Pondasi Tiang Pancang Menggunakan Data Kalendering Pada ABT1-ABT 2 Underpass STA 2+550 Binjai-Stabat

A pile foundation is needed to support the building, if the hard soil layer is very deep. The pile foundation functions to move or transfer the load above it (superstructure) to deeper soil layers. For this purpose, it is necessary to evaluate the capacity of a single pile and the capacity of a group of piles that are capable of carrying the load above them. Evaluation of pile capacity requires calendaring data in the form of field driving data which is carried out when the pile reaches hard ground with penetration and rebound values taken for 10 strokes. Based on calendaring data, single pole capacity analysis was carried out using several methods. The results of the bearing capacity analysis from one method are compared with other methods and their relationship with pile penetration. The capacity value of the pile group is calculated based on the pile efficiency. Most of the pile capacities show almost the same single pile capacity values, such as the Hiley method (666.16 kN), Navy-Mckay (752.14 kN), Janbu (440.91 kN), except that the Sanders method gives results that are much different from The value of other methods is 1138.28 kN, this could be because this method only considers the weight of the pile. The relationship between single pile capacity and pile penetration shows that the smaller the pile penetration value, the greater the pile capacity. This is obtained in all methods used, although with different calculation methods and method.

Influence of crossing fault position and site soil on the mechanical properties of bellows joint connected buried pipelines under direct shear

Buried pipeline systems are vulnerable to joint damage in earthquakes. Previous studies have shown that bellows joints are effective in increasing deformation capacity and reducing the axial force of the main pipeline. However, the effectiveness of bellows joints in enhancing the deformation capacity of the pipelines is affected by the location of the crossing fault and the soil at the site. This paper constructs and validates a finite element model of a buried steel pipeline connected by a bellows joint using ABAQUS to investigate this issue. The effects of fault location, soil properties, and internal pressure on the bellows joint connected pipelines were analyzed using a finite element model. The results indicate that the bellows joints exhibit the best energy dissipation and deformation enhancement when the fault passes directly through the joints. Bellows joints in soft soil are better at dissipating energy, reducing pipe deformation, and mitigating pipe damage compared to those in hard soils. The internal pressure is helpful to increase the mechanical properties of the pipelines. The findings can provide some guidance for pipeline design and mitigation strategies for ensuring the reliability and safety of buried pipeline systems in earthquake-prone areas.

The Abrasive Effect of Moon and Mars Regolith Simulants on Stainless Steel Rotating Shaft and Polytetrafluoroethylene Sealing Material Pairs.

For space missions to either the Moon or Mars, protecting mechanical moving parts from the abrasive effects of prevailing surface dust is crucial. This paper compares the abrasive effects of two lunar and two Martian simulant regoliths using special pin-on-disc tests on a stainless steel/polytetrafluoroethylene (PTFE) sealing material pair. Due to the regolith particles entering the contact zone, a three-body abrasion mechanism took place. We found that friction coefficients stabilised between 0.2 and 0.4 for all simulants. Wear curves, surface roughness measurements, and microscopic images all suggest a significantly lower abrasion effect of the Martian regoliths than that of the lunar ones. It applies not only to steel surfaces but also to the PTFE pins. The dominant abrasive micro-mechanism of the disc surface is micro-ploughing in the case of all tests, while the transformation of the counterface is mixed. The surface of pin material is plastically transformed through micro-ploughing, while the material is removed through micro-cutting due to the slide over hard soil particles.

The effect of soil conditions on the dynamic response of shield tunnels under train‐induced vibration loads

In this article, the influence of soil condition on the dynamic response of a tunnel and the surrounding soil was studied by both experimental model tests and numerical simulations. We tested a 1/20‐scale tunnel model with three different soil conditions: upper soft soil and lower hard soil, homogeneous soft soil and homogeneous hard soil. We also applied dynamic loads, sweep loads and train loads on the model tunnel for time domain and frequency domain analysis. The experimental and numerical results revealed that the interface between the soft and hard soil strata has an obvious amplification effect on the vibration wave. With the propagation of the vibration wave to the surface, the damping effect of the soil above the tunnel becomes the main factor affecting the dynamic response of soil. The internal force response of the tunnel structure is for the most part concentrated in the section under the excitation load, which is mainly affected by the soil properties beneath the tunnel.

ALEM-FEM-BEM coupling for response analysis of pile group in laminated fluid-saturated geomaterials induced by tunnel excavation

This paper proposes a two-stage analytical methodology for predicting the response of pile groups in layered fluid-saturated soils induced by tunnel excavation. The Loganathan analytical approach is adopted for estimating the free-field response induced by tunneling. At the second phase, the solution to the surrounding soil of pile groups is employed as the kernel function based on the analytical layer-element method (ALEM). Subsequently, the analysis of soil-structure interaction is presented using the boundary element method (BEM). The Timoshenko-beam model is utilized to simulate each monopile combined with finite element method (FEM). Finally, the responses of adjacent pile groups are derived by the coordination conditions and coupling of BEM and FEM. Comparisons are made between the presented analytical solutions and existing experimental and numerical results. Parametric analyses are performed to evaluate the influence of soil permeability, material stratification, tunnel-pile distance, tunnel buried depth, and pile slenderness ratio on the mechanical behavior of grouped piles. The results show that the pile group in hard top and soft bottom saturated soils demonstrates better load-bearing capacity than that in soft upper and hard lower soils. Then, with the increment of tunnel-pile distance, the displacement and bending moment are reduced by 22.2 %-50 % and 41.2 %-66.7 %, respectively, and the increased rate of mechanical response over time slows down. Moreover, increasing the burial depth reduces the displacement by 8.6 %-33.3 % and the bending moment by 33.4 %-50 %, respectively, and the locations of peak responses increase from 0.6 times the pile length to 0.8 times the pile length.