Hard Soil Research Articles

Analisis Struktur Lapisan Tanah Menggunakan Metode Geolistrik Resistivitas Konfigurasi Schlumberger Vertikal di Kompleks Perumahan Dosen Uncen Kali Acai, Kulurahan VIM, Distrik Abepura, Kota Jayapura

Research on the analysis of the structure of the soil layer using the Vertical Schlumberger Geoelectric method in the Lecturer Housing Complex of Uncen Kali Acai, VIM Village, Abepura District, Jayapura City. This study aims to determine the soil layer, determine the location and depth of the soft soil layer, determine the soft and hard soil. Data retrieval using geoelectric resistivity method with vertical Schlumberger configuration. The instrument used for subsurface surveys is the HV 500 AK resistivity meter. Field measurements obtained electric current and voltage values and then calculated the apparent resistivity values obtained from analysis using IP2win software to see the distribution profile, depth, and thickness of the soil layer.After doing research in the field, it can be seen that the subsurface structure at the research site is dominated by soft clay material with a resistivity value of 0.24 -692.00 Ωm. . In addition, there is a layer of hard rock in the form of a mixture of limestone with a resistivity value of 1181.00 - 8319.00 Ωm.. And the types of subsurface rocks found at the research site are clay, sandstone and limestone.

DETERMINING THE CAPACITY OF A PILE WITH THE CONDITION OF ENCOUNTERING SOIL WITH MANY LENSES

In a structural construction, one of the important parts that need to be made to support the structure is the foundation. The foundation plays a crucial role, so if there is a settlement in the foundation of a structure, an investigation is needed to address it. In a project in Serpong, South Tangerang, there is a case where there is a layer of soil with lenses, which is a condition where there is a hard soil layer with an N-SPT value greater than 50 and a thickness of about 1-4 m, this hard soil layer is located between two layers of soil with an N-SPT values less than 50. The presence of these soil lenses, located at depths of 8 m, 14 m, 24 m, and 42 m with varying thicknesses, cannot be identified through the Cone Penetration Test (CPT) and is feared to cause a settlement in the pile foundation. This is because the maximum capacity of the cone penetration test is only up to 2.5 tonf and cannot penetrate these soil lenses. This research uses soil data in the form of two boring log data, which will then be analyzed and compared for the axial bearing capacity and the settlement that occurs if the foundation piles occupy each soil condition that has a soil lens layer. The Meyerhoff and Hanna method is used to calculate the ultimate bearing capacity, while the Alpha Thomlinson method is used to calculate the settlement.

PLANNING ANALYSIS OF KALEDUPA PORT WHARF BY USING SAP2000 SOFTWARE

Kaledupa Port is a public port that serves a limited number of domestic sea transportation activities. With the growth of the tourism sector in Wakatobi Regency, especially at Kaledupa Island, the operational intensity of the Kaledupa port has also continued to increase. One of the efforts that can be made in the development of Kaledupa Port is to analyze the planning of the Kaledupa Port wharf for quality improvement and evaluation at the Kaledupa Port. This study aims to find out what kind of loads work on the wharf which can then be modeled for wharf planning in the SAP2000 software. Based on the planning analysis, the Kaledupa port wharf is planned to have a length of 82 m and a width of 10 m with a general cargo ship with a maximum weight of 1,000 DWT. The results of the wharf modeling in the SAP2000 software with steel piles with a diameter of 508 mm and a thickness of 14 mm with a carrying capacity is 86.31 tons and based on the carrying capacity of the soil at location BH-02 the soil carrying capacity is 158.88 tons at a depth of 23 m with hard soil or coral conditions.

Fractional Calculus-Based Statistical Damage Model of Unsaturated Soil under the Coupling Effect of Moistening and Stress Fields

Unsaturated soil exhibits extremely complex engineering mechanical properties under the coupling effect of moistening and stress fields. Firstly, the effective stress principle and limit equilibrium conditions of unsaturated soil under the coupling effect of moistening and stress fields were discussed based on the basic principles of unsaturated soil. Secondly, a fractional-order model considering the viscoelasticity and strain hardening of unsaturated soil was established based on the fractional calculus theory. Then, based on the principle of damage mechanics, the damage variable evolution equation under the coupling effect of moistening and stress fields was established, and the fractional calculus-based statistical constitutive damage model of unsaturated soil under the coupling effect of moistening and stress fields was developed. In turn, parameters of the developed model were solved using a triaxial test of unsaturated loess, and the calculated data using the developed model were compared with the experimental data, which demonstrated that the developed model in this paper performed well in describing the whole strain hardening process of unsaturated soil under the coupling effect of moistening and stress fields. Finally, the sensitivity of the main parameters of the developed model was discussed under the coupling effect of moistening and stress fields, which showed that the proposed model performed well in reflecting the main mechanical properties of unsaturated loess.

Экспериментальный посевной комплекс «АК-48»

The team of authors developed a new sowing complex "AK-48" with a mechanical drive of seeds, which is characterized by increased sensitivity to hard soils and climatic conditions, original design, ease of operation and maintenance, high productivity and marginality without import saturation. Comparative indicators of the cultivation of spring soft wheat variety Buryatskaya ostistaya for seed purposes according to the average separate sowing technology using a 6-meter "Bystritsa" seeder and the "AK-48" plant in CJSC "Telminskoye" of the Irkutsk region corresponds to the unambiguous distribution of the new complex. Keywords: SOWING COMPLEX, TECHNICAL CHARACTERISTICS, ECONOMIC EVALUATION

Comparative Study on Shaking Table Tests for a Pile–Nuclear Island Structure under Different Soil Conditions

In this paper, the shaking table tests of a Seismic–Soil–Pile–Superstructure Interaction (SSPSI) in medium-soft and hard base soil were carried out. Silted clay with a unit weight of 1.70 g/cm3 and a shear wave velocity of 175 m/s was adopted to simulate the medium-soft soil, while the composite soil obtained by adding 20% quicklime to silted clay with a unit weight of 1.75 g/cm3 and a shear wave velocity of 300 m/s was adopted to simulate the hard soil in the tests. By inputting the artificial seismic motion time history with different amplitudes synthesized by the RG1.60 response spectrum commonly used in nuclear power engineering to the models, the dynamic interaction characteristics and seismic response laws of the soil–pile–nuclear island structure in the medium-soft and hard base soil were compared, the internal force and deformation distribution characteristics of the pile foundation under different ground conditions were analyzed, and the site conditions and mechanism of seismic failure of the pile group foundation were described. The research results can provide a reference for site selection and seismic design of a nuclear power plant.

Fluid–Soil–Structure Interactions in Semi-Buried Tanks: Quantitative and Qualitative Analysis of Seismic Behaviors

Qualitative and quantitative assessments evaluate the structural vulnerability of liquid storage tanks. Liquid storage tanks are typically constructed and operated in areas with hard soils to minimize confining influences. However, many of these critical structures are in coastal areas with soft soils. The research conducted in this study entails the utilization of the finite element method accurately model the seismic behavior of a semi-buried concrete tank under various conditions, including changing water levels and soil properties. The study examines fluid–structure and soil–structure interactions through dynamic analyses of the rectangular semi-buried tank and comparing its different parameters. It also identifies sensitive areas where there is a probability of liquid leakage in storage tanks. The modeling is compared with the qualitative evaluation in the Japanese vibration capability diagnosis table. The results show that the tensile stress in the wall adjacent to the expansion joint is greater than the corresponding stress in the wall in all cases. In the dynamic analyses of the soil types, the pressure on the surface increases with increasing water height. A comparison of the quantitative and qualitative evaluation results shows the possible leakage of the tank in soft soil in the expansion joint.

Study on hard rock particle size division based on Mars rover traction performance

To simplify the dynamic solution of the contact between the rigid wheel of Mars rover and the spherical hard stone on the mixed terrain, a model for hard stone particle size division based on the traction performance of Mars rover is proposed. On the mixed terrain of hard rock and soft soil, the movement of hard rock will affect the traction performance of the rigid wheels of Mars rover. According to the different effects of the hard stones on the traction performance of rigid wheels, stones are divided into three types. The static sinkage of rigid wheels is calculated according to the Bekker bearing model, and the calculation formula of sliding sinkage of rigid wheels and hard stone sinkage is proposed. The type of hard stones is determined by comparing the sinkage of hard stones and rigid wheels. Finally, three kinds of hard stones with slip ratios of 0.2, 0.5, and 0.7 were substituted into the single wheel simulation platform and the soil trough experiment platform for simulation and experiment. The results show that on mixed terrain, the error of simulation and experimental results of fixed hard stones under three slip rates is below 5.4%, the error of drawbar pull in simulation and experimental results of movable hard stones is above 126%, and the error of simulation and experimental results of scattered small hard stones is below 2%, which verifies the effectiveness of the hard stone particle size division model.

Penyusunan Peta Koefisien Amplifikasi Berdasarkan Rasio Spektra Percepatan

One of the most important parameters in the building structure design process is an amplification coefficient. The amplification coefficient is needed to propagate a spectra acceleration at bedrock to soil surface. The amplification coefficient can be determined by several methods such as MASW Method, HVSR Method and other methods. One alternative method that can be used in determining the amplification coefficient is to determine the ratio between the ground acceleration at the surface and at the bedrock. Therefore, the purpose of this study was to identify the amplification coefficient in the Province of the Special Region of Yogyakarta with the PSHA method analysis approach by utilizing the shear wave velocity data (Vs30). This research method was carried out in 3 stages, namely data collection, acceleration analysis using the PSHA method, and determination of the amplification coefficient based on the acceleration ratio. The results of the study obtained a distribution of the amplification coefficient of the acceleration spectra of 0.2 and 1 second in the DIY province with a maximum value of Fa amplification coefficient was 1.414 on hard soil conditions and 1.653 on medium soil conditions. The maximum Fv amplification coefficient was 1.508 on hard soil conditions and 1,923 on medium soil conditions.

Research on irregular plane mid story isolation structures in castor earthquake prone areas considering SSI effect

The rock composition of karst area is mainly limestone, which is easy to be eroded and dissolved by water, forming a complex and fragile tectonics. Under the action of earthquake, the instability of stratum is aggravated. The mid story isolation structure is a new type of isolation structure developed from the basic isolation structure, and irregular mid story isolation buildings are highly susceptible to adverse seismic conditions. Previous studies have mostly adopted the assumption of rigid foundations, neglecting the influence of soil on irregular structures. In order to study the seismic response of isolated structures in irregular planes in karst earthquake prone areas considering soil structure interaction, a finite element model of isolated structures in irregular planes considering soil component interaction was established, and the seismic response of the structure under rigid foundation was calculated. Soft and hard soil foundations were studied, and compared with structures without considering SSI effect. Research shows that when considering the SSI effect, the seismic response of the structure increases and the damage to the structure intensifies; When considering SSI, the seismic response of soft soil is greater than that of hard soil, and the softer the soil, the more obvious it becomes; After considering the SSI effect, the torsional effect caused by the irregularity of the plane increases; The design of building structures should fully consider the adverse effects of soil layers on the seismic response of structures under plane interlayer seismic irregularities. In the design of building structures, it is necessary to fully consider the adverse effects of irregular planes on the seismic response of the structure. This consideration is particularly important in the design of soft soil high-rise buildings in karst earthquake areas to prevent unsafe designs and consider the SSI effect in actual seismic resistance.

Seismic response of multi-storied building with shear wall considering soil-structure interaction in Patna, India

The structural response of a building on soft or loose soil differs from that on hard and rocky soil. Investigating the behaviour of buildings with shear walls on such soft soil is essential. This study considers four structural models of the nine-storied building with and without infill walls. The modelled buildings represent the existing buildings in the Patna, India region. The frame was analysed in four different conditions: (1) Fixed base bare frame building, (2) Flexible base bare frame building, (3) Fixed base building with shear walls (4) Flexible base building with shear walls. Twenty-four pairs of scaled ground motion from the PEER Ground Motion Database were selected, and a nonlinear time history analysis was performed in SAP2000v20.0. Understanding that soil-structure interaction is paramount for building on soft soil, the study quantified the seismic response for the building in the Patna region, a region of high seismicity.Moreover, in current scenarios, multistorey buildings with an open ground storey and shear walls are prevalently found owing to their advantage for parking and enhancing the seismic capacity. The result shows that base flexibility significantly increases the peak floor displacement, total floor acceleration, inter-storey drift and displacement ductility for bare frame structures. At the same time, consideration of shear and infill walls only affects the flexible base structures. While shear and infill walls significantly affect the seismic behaviour of the fixed base structure. It was also found that the shear and infill walls increase the structure’s stiffness and thus reduce the fundamental vibration period of the structure. The study’s significant findings are (1) the shear and infill wall significantly reduces the seismic responses of the building, (2) base flexibility (SSI) increases the seismic vulnerability of the buildings, (3) the displacement ductility significantly depends on the aspect ratio (height/width) of the building, and (4) the inter-storey drift is relatively higher in the lower and mid storey of buildings.

Linear Macropore Installation to Reduce Red-Soil Erosion in Sugarcane Fields

This study determines the cause of soil erosion in red soils in sugarcane fields, especially even with the use of subsoiling fissures, and to compare the effectiveness of a novel artificial linear-macropore with the insertion of fibrous material into the fractures. Four column treatments (tillage, subsoiling, linear-macropore with plant residue fillings, and no-tillage-with-mulching) were established. A subsoiler was used to break up hard soil layers to enhance infiltration, whereas mulching reduced the impact of raindrops on the soil. Sugarcane residue was inserted in the empty fissure to reinforce the structure, making linear macropore. Simulated rainfall with 20 mmh−1 was applied to the soil surface for 6 h per day for two days. Surface runoff, soil erosion, and drainage were measured during each run. Erosion was minimal (1/7 reduction), and bottom drainage was observed in the linear-macropore and no-tillage-with-mulching plots. Conversely, due to the formation of an impermeable layer or surface crust, high erosion (0.282 t-C ha−1 yr−1) and decreased drainage levels were detected in the subsoiling and tillage plots. Moreover, the aboveground protrusion of fibrous material at the linear-macropore maintained infiltration, even following crust formation. Field application of these four management strategies revealed the effectiveness of linear-macropore and mulching in reducing surface flow. Linear-macropore application maintains appropriate levels of infiltration, and insertion of plant residue fillings reinforces the macropore structure while also avoiding clogging. Hence, the linear-macropore scheme may represent an effective strategy for reducing surface runoff and red soil erosion.

Anomaly Response Spectrum of Various Cities in Indonesia Based on SNI 1726:2019

Response spectra that happened anomaly is seen after SNI 1726:2012 dan SNI 1726:2019 published, this condition has happened because the value of response spectrum design is SE < SD < SC, SD < SE < SC, or SD < SC < SE, if this in normal condition, the value of response spectrum is SC < SD < SE. With applied methods and procedures found by Kircher & Associates (2015) they adjust the formula SMS & SM1 wished response spectrum becomes normal. In this research, comparing spectrum response, with spectrum response with treatment, and comparing the value SDS dan SD1. From this research, it was found that there was a decrease in seismic loading on hard soil (SC) and an increase in medium soil (SD) and soft soil (SE).

Upper Bound Solution Analysis of the Ultimate Bearing Capacity of Two–Layered Strip Foundation Based on Improved Radial Movement Optimization

Considering the change of different soil layer parameters of a two–layered strip foundation, a planar kinematically permissible multi–block failure mechanism of a two–layered strip foundation under vertical uniform load is formulated. Based on upper–bound limit analysis theorem, the solution process of ultimate bearing capacity of a two–layered strip foundation is proposed. The improved radial movement optimization (IRMO) could search the critical slip surface of the foundation and calculate associated ultimate bearing capacity. On this basis, analyze the influence parameters. The results show that the IRMO algorithm is feasible, stable, and efficient in solving the ultimate bearing capacity. With the increase in the internal friction angle and cohesion of the two–layered strip foundation, the critical slip surface will expand more deeply, and the ultimate bearing capacity will increase. The influence of upper soil parameters on the calculation results is greater than that of lower soil. For the case with upper–hard soil, the ultimate bearing capacity of it increases gradually with the increase in the H/B ratio. For the upper–soft case, the ultimate bearing capacity of it decreases gradually with the increase in the H/B ratio. Moreover, the increase of ground overload will also cause a linear–increasing in the ultimate bearing capacity.

Review of The Structure of The Bored Pile and Pile CAP The Premiere MTH Project

The Premiere MTH is an apartment complex located in South Jakarta, constructed on land with a hard soil layer extending deeper than 16 meters. Given these conditions, a bored pile foundation was selected as the optimal solution. This foundation type can be tailored to the necessary depth while minimizing disruption to nearby structures during installation. A bored pile is a type of deep foundation created by drilling into the ground to a specified depth. The process involves drilling a hole with specialized equipment, inserting a steel reinforcement cage, and then pouring concrete into the hole. Special tools are used to lift and position the casing and reinforcement. Once the concrete is poured, the casing is removed. According to the design analysis, the bored pile foundations used in this project have a diameter of 800 mm, with varying depths of 30 m and 35 m.

Evaluation of soil structure interaction effects on structural performance of historical masonry buildings considering earthquake input models

Consideration of the soil domain is significant in the evaluation of seismic response. Since, the wave propagation, soil amplifications, and deformability of subsoil significantly affect the seismic response of structures. For this reason, the effect of soil-structure interaction and soil condition should be considered in the evaluation of the seismic response of structures. This paper presents a seismic performance evaluation of a historical masonry building considering different soil conditions and earthquake input models. The building investigated in this study dates back to the 1870 s. The seismic performance of the building was evaluated with a new guideline specifically published for the assessment of historical structures. At the end of the analyses, natural frequencies, mode shapes, maximum displacements, and principal stresses were obtained and presented in detail. In terms of drift ratio control, the building showed only limited damage during the applied earthquake record. Also, in general, the requirement for the stresses was satisfied. This means that the building behaved in a linear response. While the natural frequency values decreased from the hard soil condition to the soft soil condition, the drift ratios increased for each earthquake input model. The maximum differences between natural frequencies obtained from massless-soil and massed-soil SSI systems increased from the hard soil to soft soil conditions. It was concluded that the soil models with mass or without mass did not affect the frequencies too much in the hard soil condition, but it was quite effective in medium and soft soil conditions. It was clearly seen that there were differences between the results obtained from earthquake input models based on different soil conditions. In this context, it should be noted that the soil-structure interaction of historical masonry structures sensitive to seismic effects should be considered depending on different earthquake input models. As a matter of fact, it was thought that it is necessary to contribute to the studies available in the literature in this field.

Structural behavior of a seismic-isolated stadium grandstand considering hard and soft soil conditions

La principal aplicación del aislamiento sísmico a nivel mundial está en edificaciones y puentes, sin embargo, puede ser aplicada a cualquier estructura. La técnica, teóricamente, tiene limitaciones de uso por eficiencia, como en edificaciones altas y suelos blandos. En este artículo se estudia una estructura aislada no convencional, para evaluar los beneficios del aislamiento sobre esta. Específicamente se analiza una tribuna de estadio localizada en Colombia, con condiciones de suelo duro y blando. La estructura es importante, debido a su necesidad de mitigación del riesgo por sismo. Esta considerará un alto número de personas que deben evacuar de forma segura durante terremotos y después de estos, la estructura podría ser destinada a refugio humanitario. Los resultados a) muestran beneficio estructural principalmente en condiciones de suelo duro, b) corroboran y cuantifican las limitaciones de los suelos blandos y c) permiten generar algunas recomendaciones para aislar estructuras bajo las condiciones aquí estudiadas.

PERKUATAN DINDING PENAHAN TANAH EKSISTING SETINGGI 8 -1000mm YANG MEMBAHAYAKAN MASYARAKAT DI RANGKASBITUNG

ABSTRACT
 The team observed the condition of the walls, gathered information from building owners, combined the received information and finally conducted an engineering analysis. Based on this study, the best recommendation was obtained for the building owner to make an additional strengthening structure in the form of a combination of reinforced concrete column and beam with a cross section size of 300 x 300mm. The strengthening structure installed in the form of right triangles as high as the retaining wall. The strengthening structure located 1500mm apart. The strengthening column and beam are supported by two 300mm diameter drilled pile foundations tied together by 1500 x 300 x 300mm pile caps. The drilled pile foundation is buried to a depth of 600mm lying on above hard layer soil. Between strengthening structures that are 1500mm apart are tied with reinforced concrete beam with a 300 x 300mm cross section to unite the strengthening structure. In conducting this study of solving the continuing damage of retaining wall the lecturers and students discussed to find the most appropriate study for the solution to the existing retaining walls. Detailed calculations and drawings are carried out by students and lecturers giving suggestions and directions until conclusions are obtained and recommendations are made to building owners. Recommendations were submitted to the building owner and then implemented the Team's recommendations by constructing the strengthening structure, until finally the strengthening structures had been installed on the 8000 and 10000mm high retaining walls.

Thermo-mechanical analysis of pipe energy piles in layered cross-isotropic soils

This paper aims to propose a method for the thermo-mechanical analysis of pipe energy piles in layered cross-anisotropic soils. Firstly, the pipe pile is modelled as a bar and the stiffness matrix equation considering thermo-mechanical loads is established based on the finite element method (FEM). The soils are considered to be layered cross-anisotropic and the boundary element method (BEM) is employed to obtain the deformation-force relationship of the soil-pile nodes. Afterwards, the coupled BEM-FEM equation is developed according to soil-pile deformation coordination conditions. The proposed method is verified with responses of pipe piles, solid energy piles and pipe energy piles. Parametric analyses show that the performance of the pipe energy pile induced by heating needs considering in the design of the pipe pile thickness, and the induced tensile stress should be taken into account in the design in hard soils. Besides, the influence of cross-anisotropy on the performance of the pile under cooling is larger than that under heating, and a softer surface soil layer yields a smaller axial force of the pipe energy pile for layered soils.

Influence of Soil Flexibility on Seismic Behavior of RC Buildings with Shear Wall

The seismic response of a structure is very complex owing to the behavior of soils during an earthquake. The importance of including the soil–structure interaction (SSI) effect in building frame analysis is quickly recognized, but the modeling of SSI is complicated. The present paper investigates the seismic response of a RC building incorporating soil–structure interaction. The research focuses on clayey soil conditions in situ, taking into account soft, medium, and hard soil. The SSI effect is accounted for by using a point spring element and a fixed support condition. For the study, a RC ground (G)+10-story building with a basement is considered with L-shape (L-SW) and T-shape (T-SW) shear walls resting on a raft foundation. To comprehend the different circumstances of the soil on the structure for comparison study, the responses of some parameters such as story drift, story displacement, and base shear are obtained. The findings of the study show that including SSI effects in the seismic design of multistory buildings is critical because it can result in a significant reduction in controlling design forces without compromising the structure’s safety. Moreover, assuming a fixed base can lead to a high overestimation of the structure design forces and seismic response. The aim of the present study is to obtain the behavior of the RC building under different soil conditions considering two types of shear walls.