Maximum Axial Force Research Articles

Numerical investigation on performance of nail stabilised vertical cuts

Soil nailing is an earth retention technique commonly used for stabilising steep slopes, retaining excavations and helps in maintaining the ground surface at two different elevations. Ease of installation, economic efficiency and effective performance of soil nailed structures under different loading conditions has resulted in the rapid use of the technique in different temporary and permanent construction applications. This study deals with the finite element analysis of 6 m and 10 m high vertical soil nailed walls to evaluate the performance under static loading. The characteristics of structures are evaluated under different nail inclinations, nail lengths and different site conditions. The response of soil nailed structures under different parameters are assessed with respect to maximum horizontal displacement of the wall, maximum axial force developed along the nail length and lateral earth pressure distribution on the nailed wall. An optimum nail inclination of 15° and nail length ratio of 0.7 has been identified as best suited for a stable vertical cut.

Investigation on the Stress and Deformation Evolution Laws of Shield Tunnelling through a Mining Tunnel Structure

In the construction of a shield crossing an existing mined tunnel without load, it is imperative to develop corresponding design standards that reflect actual engineering force characteristics to ensure the successful completion of the tunnel construction. This study uses the MIDAS-GTS NX 2022 finite element software to facilitate the creation of a numerical model of a shield structure for an air-push-over mine tunnel project in Changsha, China while investigating the stress field’s evolution during shield construction and calculating the maximum positive and negative bending moments and maximum axial forces for different structures and other force states under various construction conditions. This study’s findings informed the design and construction optimisation of a shield tunnelling empty-push method. The outcomes of this numerical simulation led to several key findings: (1) The soil density exerted a significantly greater impact on the internal forces of the initial support structure than both the tunnel depth and soil Poisson’s ratio. Additionally, a sudden shift in internal forces occurred within the 300–350 mm range when the lining thickness was altered. (2) Factors such as the tunnel depth, soil density, soil Poisson’s ratio μ, and lining thickness similarly influenced the internal forces of the segment and the initial support. Notably, the backfill layer thickness significantly affected the segment’s maximum axial force, causing an abrupt change of approximately 300 mm. (3) It is essential to control the guide rail’s thickness under the shield machine equipment’s weight constraint to prevent it from becoming overly large.

Finite Element Analysis of Cortical Bone Trajectory Screw Resistance to Pullout During Exposure to Different Cortical Layers Based on AbaqusCEA Software.

To investigate the maximum anti-pullout force and stress distribution of cortical bone trajectory (CBT) screws during screw pullout after contacting different cortical bone layers by finite element analysis (FEA) based on Abaqus software, and to provide evidence for increasing screw holding force during CBT screw implantation in clinical practice. Based on the plain CT data of lumbar spine of a healthy male volunteer who visited the Fourth People's Hospital of Guiyang in June 2022, and the standard screw parameters according to cortical bone trajectory screws. A three-dimensional model of L4 vertebral body and CBT screw was established. The diagnostic criteria of osteoporosis by quantitative CT of lumbar spine in China were set as 120mg/cm3 low bone mass model. According to the number of contact layers between screws and cortical bone, the models were divided into group A: CBT screws produced one layer of cortical bone contact with the vertebral body (screw implantation point); group B: CBT pedicle screws produced two layers of cortical bone contact with the vertebral body (screw implantation point + pedicle inner edge); group C: CBT pedicle screws produced three layers of cortical bone contact with the vertebral body (screw implantation point + pedicle inner edge + outer edge of the vertebral body); group D: CBT pedicle screws produced four layers of cortical bone contact with the vertebral body (screw implantation point + pedicle upper wall + pedicle lateral wall + upper edge of the vertebral body); group E: CBT pedicle screws produced five layers of cortical bone contact with the vertebral body (screw implantation point + pedicle posteromedial medial wall + anterolateral wall of the pedicle + upper edge of the vertebral body + outer edge of the vertebral body). According to the reference, after the material assignment was completed, the axial pullout force experiment of screws was simulated on Abaqus CEA engineering software for five groups of finite element models established to observe the maximum axial pullout force of each group of models and the stress distribution of screws and vertebral bodies. For the comparative analysis between each group of models corresponding to the measured data, one-way analysis of variance was used. The stress of cancellous bone failure in finite element model of group E was (8.6 ± 0.9), (8.4 ± 0.9), (8.1 ± 0.9), (8.3 ± 0.8), and (8.8 ± 0.7) MPa, respectively, and there was no significant difference between any group (P > 0.05); the maximum principal stress in the tail of screw was (195.1 ± 35.8), (290.9 ± 32.1), (317.3 ± 44.5), (396.3 ± 51.2), and (526.5 ± 53.1) MPa, respectively, and the stress in cortical bone destruction was (40.6 ± 3.5), (52.6 ± 4.2), (89.4 ± 4.9), (109.0 ± 8.3), and (129.4 ± 6.4) MPa, respectively, and there was significant difference between any group (P < 0.05); the maximum axial pullout force in group A-E was (1890.5 ± 45.0), (1913.4 ± 53.8), (2371.0 ± 108.3), (237.2 ± 43.0), and (119.5 ± 43.0), respectively. The increases were 2%, 16%, 5%, and 7%. There were significant differences between each group and group E (P < 0.05). Axial pullout force increases as the number of contact layers between CBT screws and cortical bone increases. The axial pullout force increases most when the cortical trajectory screw contacts the vertebral body with three layers of cortical bone, and reaches the maximum value when the number of contact layers reaches five layers, regardless of the screw tail stress and the maximum axial pullout force, so it is clinically desirable to make the screw contact more than three layers of cortical bone to obtain higher stability during screw implantation, improve screw stability, and increase the surgical fusion rate.

Optimal design method of the load-level isolation system for industrial steel racking

This paper focuses on an innovative system for mitigating seismic actions on industrial steel racking, called Load-Level Isolation System (LLIS). It consists of placing isolators directly between the pallet masses and the load level, thus exploiting the pallet masses (much greater than the structural mass) as tuned mass dampers. Specifically, the paper aims to derive a general design procedure for the LLIS, based on the amount of mass isolated, the position of the LLIS within the rack, and the main dynamic characteristics of the structural system. To this end, an analytical optimization method is proposed, based on the minimization of the displacement variance of a reduced structural model, representative of the rack dynamics with the LLIS. This method is applied parametrically to derive the optimal damping and frequency values of the LLIS in various design situations, and a sensitivity analysis is subsequently conducted to propose cost-effective LLIS design solutions. Prediction models of the LLIS parameters are therefore provided, as well as a simple step-by-step procedure for designing the control system. Finally, a case study is presented, with the dual objectives of showing the application of the design procedure and the effectiveness of the LLIS in mitigating seismic effects in a standard pallet rack. The results of the Time-History analysis demonstrate the validity of the proposed design method and the possibility of achieving large reductions in the seismic response of the rack using this control system, and up to 60% for both maximum displacements and axial forces of the uprights.

Analysis of the Conventional Steel Building and Pre-Engineered Building Structures for Various Bay Lengths

Abstract: Comparing PEB structures to conventional structures is the main goal of this study. Pre Engineered Buildings (PEB) are constructions that are manufactured and assembled on site. This study assesses both traditional steel structures and preengineered structures. Usually, industrial buildings are built using this kind of structural principle. An industrial structure with 5 and 6 m-long bays is under consideration. STAAD PRO software is used for structure analysis. In this study, the maximum reaction, maximum stress analysis, and maximum axial force results for conventional steel structures and pre-engineered structures with bay lengths of 5 and 6 metres are examined and compared. We consequently conclude that PEB is preferable to CSB.

Influence of complex loading of radial bearings of the oscillation groups of liquid propellant engine steering gear on the frictional moment

The paper presents a method for determining the frictional moments of the oscillation groups of the most widespread domestically made liquid propellant engine steering units. This is a topical issue requiring investigation to improve the efficiency and reliability of oscillation groups. The reason for the occurrence of an additional axial force in the radial bearings of the articulated joints that leads to an overestimation of the actual values of the moments relative to the theoretical values is shown. The procedure for calculating the maximum axial force and the accompanying increase in the moment, confirmed by the analysis of the results of the bench test of the experimental steering unit, is presented. An assessment of the range of axial forces in the absence of blocking of the axial movement of the bearing was carried out with a simultaneous analysis of the suitability of the existing methods for calculating the increase in the frictional moment for the obtained ratios of axial and radial loads. The direction of further research of low-speed radial bearings is determined, aimed at increasing the reliability of calculations and developing measures to minimize the frictional moment of production oscillation units.

The Cold Forming Analysis of Eccentric Parts

In this study, a multi-stage cold forming process for the manufacture of eccentric parts is studied numerically with low carbon steel AISI 1022. The forming processes through five stages and four stages include two-step forward extrusion, eccentric upsetting, and backward extrusion over a moving punch. The numerical simulations of cold forming are conducted using the code of DEFORM-3D. The formability of the workpiece is studied numerically, such as the effect on forging load responses, maximum forging loads, effective stress and effective strain distributions and metal flow pattern. The maximum effective stress of 819 MPa at the third stage is the largest among the stages. The maximum effective stresses of the last stages for the four-stage forming and five-stage forming are almost the same. The effective strain distributions of the last stages for the four-stage forming and five-stage forming are very similar. The flow line distributions of the last stages both for the four-stage forming and five-stage forming are also very similar. For the maximum axial forging force and forming energy, the third stage of eccentric upsetting at the upper end is the largest among the stages. The total maximum axial forging loads from the first to the last stages are 795.8kN for the five-stage forming and 590.4kN for the four-stage forming; and the total forming energies are about 0.751kJ for the five-stage forming and 0.671kJ for the four-stage forming. Although the total maximum axial forging loads and total forming energy of the four-stage forming are smaller than those of the five-stage forming, the maximum lateral forging force in the last stage of the four-stage forming is almost five times that of the last stage of the five-stage forming. Increasing lateral forging force may lead to wear and damage of the punch. Moreover, the inner surfaces of the hexagonal cavity at the upper end are relatively uneven because of simultaneous eccentric upsetting and backward extrusion in the last stage of the four-stage forming.

Research on the influence of foundation pit excavation on the lateral force and deformation of side shield tunnels based on full-scale experiments

To explore the internal force and deformation response law of the Hangzhou subway shield segment under the influence of the excavation and unloading of the side foundation pit, the self-developed “shield segment hydraulic loading system” was used to carry out full-scale loading tests on the three-ring staggered assembled segments. A preloading loading test were performed before the formal experiment to determine the loading method of the initial confining pressure. Analyzed the change mechanism of the internal force and deformation of the segment structure are influenced by factors such as the foundation pit and the tunnel clear distance. A numerical model is established based on the experimental results, and the influencing parameters that are difficult to complete in the experiment, such as the depth of the tunnel, are analyzed in detail. The research results show that the equal load maintains a balanced state of the segment to the greatest extent, and its internal force and deformation results are large, which is suitable for this experiment. After the excavation of the foundation pit, the maximum positive and negative bending moment increases, while the maximum axial force decreases. The average maximum recovery rate of tunnel section is 15.6%. Moreover, the additional internal force and deformation of the segment will increase with increasing deformation parameters of the envelope structure and decrease with increasing clear distance between the foundation pit and the tunnel. The bending moment of the segment is more sensitive to changes in the confining pressure, the convergence change can be controlled within a limited range, and the trend of the change in the internal force of the bolt shows differences. The numerical model established in this paper can better analyze the stress state of the tunnel. When the tunnel is buried deep in the slightly upper position of the excavation surface of the foundation pit, the unloading effect that is received is largest.

Eccentric Rotor Drop Dynamics Study of Vertical Maglev Bearing System

When considering the problem of a vertical magnetic levitation bearing system, the rotor eccentric fall is more likely to cause the failure of the protective bearing. In this paper, a rotor drop collision model and a protective bearing dynamics model are constructed. It compares and analyzes the evolution of collision force values of the rotor eccentric drop as well as the non-eccentric drop. Further, this paper discusses the law of influence of three factors, rotor quality, rotational speed, and axial protection clearance, on the collision characteristics of the protected bearing in eccentric and non-eccentric cases. It has also experimentally verified this characteristic of rotor speed. The results show that compared with the non-eccentric condition, the axial impact force and radial impact forces of the rotor in the eccentric condition increase by 14% and 114%, respectively. Compared with the non-eccentric condition, with the increase in rotor quality, the axial and radial impact force increase by 68% on average, and the axial depth amplitude of the rotor increases by 350%. With the increase of rotor speed, the axial impact force without an eccentric drop is basically unchanged; the axial impact force of an eccentric drop increases slightly, and the radial impact force increases by 110%. With the increase of axial protection clearance, the radial displacement vibration of the rotor axis increases; the average increase of the maximum axial force is 120 N, and the average increase of the maximum radial force is 100%.

Comparative Analysis and Experiment Verification of Diamagnetically Stable Levitation Structure

In this paper, a new diamagnetic levitation structure is proposed to explore its potential in the application of sensors and actuators through the study of its levitation and dynamic characteristics. Compared with our old diamagnetic levitation structure, the levitation point, maximum monostable levitation space, horizontal magnetic spring stiffness, and axial resultant force distribution of the new structure are all adjustable. At the same time, the maximum horizontal radial recovery force of the floating magnet could reach 34780 μN, which is 542.41% higher than that of the floating magnet in the old structure. Accordingly, when the range of the horizontal radial displacement is 0 to 15 mm, the maximum axial resultant force of the floating magnet is 439.7 μN, which is only 5.72% of that in the old structure. In experiment, when the floating magnet is blown by nitrogen gas with a flow rate of 3000 sccm, the maximum horizontal radial displacement of the floating magnet is 2.27 mm, which is only 22.976% of that in the old structure. Under the same gas flow rate, the maximum tilt angle of the floating magnet is 0.482°, which is only 3.998% of that in the old structure. In summary, the theoretical analysis, numerical simulation, and experiment results are consistent with each other, which indicates the great potential of the new structure in the application of sensors and actuators.

Experimental Study on the Negative Skin Friction of Piles in Collapsible Loess

The collapsible loess is widely distributed in western China. The special structure and water sensitivity of loess lead to the complex negative skin friction mechanism in pile foundations. Previous studies mainly focused on the negative skin friction of pile foundations and treatment measures, such as casing and coating methods. However, few studies have focused on the influence of the negative skin friction on the settlement and bearing capacity of piles in collapsible loess, especially environmentally friendly methods that can reduce the negative skin friction. In this study, a series of non-immersion and immersion experiments was conducted to investigate the settlement, axial force, and side friction resistance of piles in loess soil under controlled conditions. The results showed that under the non-immersion condition, the settlement of model piles increased with the increasing pile top load. The axial force gradually decreased along the pile length for piles without casing. The axial force attenuation of the casing section of casing piles was almost negligible due to the isolating frictional resistance effect of casing. The settlement of each soil layer increased with the increase in immersion time, and the process was divided into an initial gradual stage, rapid drop stage, and later gradual stage. Both negative and positive skin friction increased with the increasing immersion time and pile top load, and there was a neutral point. The maximum axial force of piles without casing exceeded the peak load at the pile top. The presence of steel casing reduced the failure of pile foundation in collapsible loess. The research results of this paper provide theoretical support for the application of piles in loess areas.

Influence of design load determination method for SC-BRBs with trilinear flag-shaped hysteresis behaviour on the seismic performance of braces and structures

Self-centering buckling-restrained braces (SC-BRBs) can effectively reduce the residual deformation and seismic damage of the main structure. Because the first loading curve and subsequent loading curve of SC-BRB trilinear flag-shaped hysteresis behaviour do not coincide, there are two ways to determine the design load of a brace, i.e., the design load is taken as either the bearing force Fy1 at the first stiffness change point of the first loading curve or the bearing force Fy2 at the stiffness change point of the subsequent loading curve. In this study, a numerical analysis method is used to study the differences in the hysteresis performance of braces (i.e., SC-BRB-Fy1 and SC-BRB-Fy2) and the seismic performance of structures (i.e., SCBF-Fy1 and SCBF-Fy2) based on different design load determination methods. The results demonstrate that when the strength ratio β and the first stiffness ratio αc are similar, the hysteresis performance of braces and the seismic performance of structures are basically the same regardless of the method of design load determination. Decreasing β or increasing αc significantly increases the maximum axial force of SC-BRB-Fy1 but has little effect on that of SC-BRB-Fy2. Decreasing β can enhance the energy dissipation capacity of braces, reduce the maximum displacement of structures during earthquakes, and reduce the deformation concentration effect of SCBF-Fy2 but has no obvious influence on the deformation mode of SCBF-Fy1. Increasing αc can improve the energy dissipation capacity of SC-BRB-Fy1 but weaken the energy dissipation capacity of SC-BRB-Fy2, which has the opposite effect on the displacement response of SCBF-Fy1 and SCBF-Fy2.

Mechanical Behavior of Fully Grouted Rock Bolts in Hydraulic Tunnels Subjected to Elevated Ground Temperatures

In this study, the mechanical behavior of fully grouted rock bolts in hydraulic tunnels subjected to elevated ground temperatures was investigated. A differential equation for axial displacement of the rock bolt was formulated, which considers the force equilibrium of infinitesimal bolt segments and the stress transfer mechanism at the anchor–rock interface. The distribution functions for axial stress within the bolt and the interfacial shear stress were obtained by solving the differential equation, which incorporated the displacement of the surrounding rock mass as a parameter. This study showed that the effectiveness of the bolt–shotcrete support system decreases over time, considering the displacement relaxation rate of the surrounding rock mass. The mechanical model’s variation laws at 20 °C, 50 °C, and 80 °C were summarized by integrating the thermal deformation equation for material parameters, and the numerical simulation results were compared and analyzed. The findings revealed that the bond strength between the rock bolt and the rock mass diminishes as the temperature of the surrounding rock increases, leading to a reduction of interfacial shear stress at both extremities of the bolt. Moreover, the maximum axial force within the bolt escalates as the neutral point migrates farther from the tunnel wall.

Second-generation bone cement-injectable cannulated pedicle screws for osteoporosis: biomechanical and finite element analyses

BackgroundBiomechanical and finite element analyses were performed to investigate the efficacy of second-generation bone cement-injectable cannulated pedicle screws (CICPS) in osteoporosis.MethodsThis study used the biomechanical test module of polyurethane to simulate osteoporotic cancellous bone. Polymethylmethacrylate (PMMA) bone cement was used to anchor the pedicle screws in the module. The specimens were divided into two groups for the mechanical tests: the experimental group (second-generation CICPS) and control group (first-generation CICPS). Safety was evaluated using maximum shear force, static bending, and dynamic bending tests. Biomechanical stability evaluations included the maximum axial pullout force and rotary torque tests. X-ray imaging and computed tomography were used to evaluate the distribution of bone cement 24 h after PMMA injection, and stress distribution at the screw fracture and screw–cement–bone interface was assessed using finite element analysis.ResultsMechanical testing revealed that the experimental group (349.8 ± 28.6 N) had a higher maximum axial pullout force than the control group (277.3 ± 8.6 N; P < 0.05). The bending moments of the experimental group (128.5 ± 9.08 N) were comparable to those of the control group (113.4 ± 20.9 N; P > 0.05). The screw-in and spin-out torques of the experimental group were higher than those of the control group (spin-in, 0.793 ± 0.015 vs. 0.577 ± 0.062 N, P < 0.01; spin-out, 0.764 ± 0.027 vs. 0.612 ± 0.049 N, P < 0.01). Bone cement was mainly distributed at the front three-fifths of the screw in both groups, but the distribution was more uniform in the experimental group than in the control group. After pullout, the bone cement was closely connected to the screw, without loosening or fragmentation. In the finite element analysis, stress on the second-generation CICPS was concentrated at the proximal screw outlet, whereas stress on the first-generation CICPS was concentrated at the screw neck, and the screw–bone cement–bone interface stress of the experimental group was smaller than that of the control group.ConclusionThese findings suggest that second-generation CICPS have higher safety and stability than first-generation CICPS and may be a superior choice for the treatment of osteoporosis.

Study on the Mechanical Characteristics and Ground Surface Settlement Influence of the Rise–Span Ratio of the Pile–Beam–Arch Method

The pile–beam–arch method (PBA) method is increasingly being used in the construction of metro stations with complex traffic conditions. The rise–span ratio of the arch not only affects the height of the station, but also affects the rationality of the design of subway stations and the safety of construction. The mechanical response of steel pipe piles with different rise–span ratios and the effect of controlled surface settlement have been investigated in the interactions involved in pile–soil system. In this paper, the finite element model of each rise–span ratio was established, and the rationality of the model was demonstrated by comparing the numerical simulation calculation with the field surface settlement monitoring data. The mechanical characteristics and influence analysis of the surface deformation during the excavation of the cave pile method were investigated. The results show that the maximum axial force of the central pile first decreases and then increases with the increase in the rise–span ratio. The maximum bending moment of the arch decreases as the rise–span ratio increases, and the maximum axial force of the arch is negatively correlated with the rise–span ratio. The maximum axial force of the central pile is located at the bottom plate. Due to the symmetry of the structure, the bending moment of the centre pile is small, but the maximum bending moment of the whole station is located at the side wall of the bottom plate. As the rise–span ratio increases, the surface settlement first decreases and then increases. The construction of the pilot tunnel and the upper arch is the most important factor leading to the surface settlement, so it is necessary to strengthen the soil layer.

Comparative Analysis of Composite Structure by STADD Pro Software

Abstract: In comparison to many other emerging nations, India uses a fairly little amount of steel in the construction industry. Other nations' experiences suggest that this isn't because steel isn't economically viable as a building material. Maximum Axial Forces On Column Base Of The Structure Column RCC Structure (kN),steel Structure (kN) ,Difference in Foundation Size and Reinforcement Requirements Property RCC Structure, Steel Structure Size:- are found by staad pro software. .With the existing development requirements in India, there is a tremendous opportunity for raising the volume of steel in teaching. A significant loss for the nation results from not utilising steel where it is cost-effective as an alternative construction material. Also, it is clear that modern composite sections made of steel and concrete are a time, money, and cost-effective alternative for important civil structures like bridges and tall skyscrapers.

Nozzle Jet Deviation from Bucket Pitch Circle’s Effect on the Stability and Efficiency of Pelton Turbine

During the operation of a Pelton turbine, the centerline of the nozzle jet may deviate from the bucket pitch circle due to the low installation and maintenance accuracy, which will reduce the operating efficiency and the stability of the turbine and even cause severe vibrations and damages. Based on the VOF (Volume of Fluid) two-phase flow model and the SST k-ω turbulence model, the flow characteristics of a Pelton turbine were simulated with the nozzle jet deviating from the bucket pitch circle. The pressure pulsation inside the bucket and the force distribution of the runner were obtained, the turbine oscillation and efficiency were measured before and after the jet deviation, and the effects of the radial and axial deviations on the stability and efficiency of the Pelton turbine were analyzed. The results show that both the radial and axial deviations of the jet cause a significant increase in the axial force and the pressure pulsation amplitude of the turbine; the radial and tangential forces on the runner are slightly reduced; the maximum axial force on the runner is increased by 4 times and 2 times, respectively, after the axial and radial deviations within the maximum value allowed by the industry standard; and the efficiency of the turbine is reduced by 0.4% and 0.3%, respectively. The maximum relative amplitude of pressure pulsation in the radial offset case appears in the center of the bucket blade, while the axial offset case causes uneven pressure distribution on both sides of the diverter blade, uneven force on the bucket blade of the runner, and fatigue damage. By comparing the operation of the runner under the two offset cases, we can find that the axial offset of the jet has a greater impact on the stability of the runner than the radial offset, and the unit is more prone to vibration, increasing the risk of the unit lifting.

Seismic performance of RC frame structure across the earth fissure based on pushover analysis

This study aims to investigate the seismic performance and failure mechanism of reinforced concrete frame structures across the earth fissure. A five-story reinforced concrete frame structure across the earth fissure was tested by shaking table and the test equivalent finite element model was established by simulation software, the seismic performance of the reinforced concrete frame structure across the earth fissure was carried out and analyzed by these two methods. The results showed that the earth fissure has an amplification effect on the structure displacement response, the damage indexes and internal forces of the structure across the earth fissure were always larger than the structure on the ordinary site. The maximum damage index deviation increases from 6.1% to 11.4% under 0.2 g and 0.4 g seismic waves, and the maximum axial and shear forces deviation of column increases from 29% to 50% and 11.7% to 15.2% during 0.2 g to 0.6 g Cape Mendocino waves, respectively. With the increase of seismic intensity, the deviation of damage indexes and internal forces increased. The damage to the structure of the hanging wall were earlier and more seriously, and the first floor was the most vulnerable floor. The research in this paper has practical significance for seismic performance evaluation and provides reference for reinforced concrete frame structure across the earth fissure seismic design.

Study on Impact of Various Void Conditions on Shallow Rectangular Masonry-Concrete Power Tunnel and Surrounding Roads

To solve the problem of a potential void near a shallow rectangular masonry-concrete power tunnel, the ground-penetrating radar (GPR) detection technology is used and multiple GPR detection lines are placed to detect concealed void. The GPR images of circular and square voids are obtained, which can help increase accuracy of void identification. The models that cover 9 circular voids and 9 square voids are created to investigate how various forms and positions of void will affect the internal forces of the power tunnel structure and surrounding roads. In terms of morphological characteristics, according to the research results, the impact of a circular void on tunnel and surrounding roads is slightly stronger than that of a square void. If the circular void and square void are at 135° and 115°, respectively, the maximum shear force of the tunnel structure occurs at the floor. If both circular and square voids are at 115°, the maximum axial force of tunnel structure occurs at the right side wall. If both circular and square voids are at 135°, the maximum bending moment of tunnel structure occurs at the floor. If both circular and square voids are at 155°, the ground settlement and pavement stress of surrounding roads are maximized. Generally, if a void occurs at the middle or lower part of the side wall or near the side of the floor in a shallow rectangular masonry-concrete power tunnel, its adverse impact is at its worst. Therefore, GPR detection of the voids at the lower and middle parts and the side of the floor in the power tunnel should be intensified, in order to eliminate the risk of a void near power tunnel.

Analysis and Design of Steel Silo using STAAD.ProV8i

Generally silo is a storage structure for heavy bulk materials such as cement coal, wood, food products and saw dust. Its design involves materials, geometry, and structural considerations. This research considered a special structure steel silo treated with myriad conventional and unconventional loading conditions, varied from some tonnes to many of tonnes which findings in uncommon modes of failure. Silo Specifications of 14m height and 3m diameter was designed with section ISMB 300 and ISA 70x70x10mm as per Indian standards. In addition, the plan and section of the silo wad done by the AutoCADD 2018 software. modelling, dynamic analysis and designs were completer in STAAD PRO V8i.Besides, the silo was designed as per Indian standards IS 800.The maximum axial force and shear force of the steel silo were 15.9 KN and 0.037 KN respectively. The aim of this paper was to determined the Plate stress, contour lines, and critical support of the silo, beam end force summary and steel take off of the silo structure.&#x0D; Generally silo is a storage structure for heavy bulk materials such as cement coal, wood, food products and saw dust. Its design involves materials, geometry, and structural considerations. This research considered a special structure steel silo treated with myriad conventional and unconventional loading conditions, varied from some tonnes to many of tonnes which findings in uncommon modes of failure. Silo Specifications of 14m height and 3m diameter was designed with section ISMB 300 and ISA 70x70x10mm as per Indian standards. In addition, the plan and section of the silo wad done by the AutoCADD 2018 software. modelling, dynamic analysis and designs were completer in STAAD PRO V8i.Besides, the silo was designed as per Indian standards IS 800.The maximum axial force and shear force of the steel silo were 15.9 KN and 0.037 KN respectively. The aim of this paper was to determined the Plate stress, contour lines, and critical support of the silo, beam end force summary and steel take off of the silo structure.