Steel Support Research Articles

Sintered Clays: Application in the Removal of Arsenic from Water by Filter Beds

Objectives: The main objective of the research was to build a ceramic filter bed, using red clay and diatomite, for the removal of arsenic in aqueous media and to propose an environmentally friendly and low-cost technique for rural communities in Peru that consume water contaminated with arsenic. Theoretical framework: Arsenic is a common contaminant in the drinking water of many rural communities in Peru, exceeding the limits allowed by the WHO. Prolonged exposure to arsenic can cause serious health problems. The use of low-cost non-metallic materials, such as thermally activated clay and diatomite, is proposed for its adsorption. Method: A filter bed composed of 5 cm layers of red clay and diatomite with particle sizes of 0.81, 0.31 and 0.20 mm was used. Both materials were thermally activated at 900°C and placed on a stainless steel support. The arsenic removal process was evaluated by passing a synthetic solution with 13.99 ppm of arsenic through the bed. Material characterization analyses were performed before and after the adsorption process, using techniques such as ICP-OES, SEM, FTIR, among others. Results and discussion: The filter bed composed of diatomite (83.31% SiO2) and red clay (8.23% Fe2O3) achieved an arsenic removal of up to 99.99%, highlighting the efficiency of particles with a size of 0.20 mm. This shows that the combination of these materials can be highly effective in removing arsenic in water, which is promising for its implementation in rural areas. Research implications: This research has important implications for water treatment in rural communities facing arsenic contamination problems. The technique developed is low-cost and uses abundant resources, which facilitates its application at the local level and promotes sustainable solutions for access to safe drinking water. Originality/Value: The research provides a novel approach through the use of red clay and diatomite, accessible resources, thermally activated for the removal of arsenic in water. In addition, the high removal effectiveness achieved provides a potentially scalable and replicable solution in other rural communities with similar problems.

3D printed steel monoliths for CO2 methanation: A feasibility study

Steel honeycomb monoliths have been manufactured by Fused Deposition Modelling-FDM 3D printing technology using 90 % 17–4 PH steel nanoparticles-loaded polymer filament. Pure steel monoliths were obtained after thermal removal of the polymer and steel sintering. NiO-CeO2 active phase nanoparticles were loaded on powder steel and on the steel monoliths, and the supported catalysts were tested in the hydrogenation of CO2 to CH4, paying special attention to the steel pretreatment before active phase loading. The catalytic experiments confirm that totally functional catalysts have been prepared, showing 100 % selective conversion of CO2 to CH4 above 225 ºC and stability in long-term experiments (18 hours at 325 ºC). The catalytic behaviour is improved by H2O2-pretreatment of the steel honeycomb monoliths before the active phase loading. XPS characterization confirms that the surface of the catalysts is oxidised on the fresh catalysts and gets even more oxidised after the catalytic tests. The H2O2-pretreatment of the steel support partially avoids the additional oxidation under reaction conditions, keeping chromium and cerium cations less oxidised than on the catalyst prepared with untreated steel. In addition, evidence about the electronic interaction between the steel support and the NiO-CeO2 (np) active phase are obtained.

Highly selective thin B-oriented MFI zeolite membranes on scalable modified stainless steel supports

Enhancing the separation performance of molecular sieve membranes relies significantly on precise control over their membrane morphology and microstructure. This involves creating thin, closely packed, oriented, and uniform coatings of seed crystals, enabling subsequent intergrowth to establish continuous membranes. To address industrial needs, it is crucial to generate a thin and flawless membrane efficiently producible on a large-scale support. Porous stainless supports offer scalability and easy integration into membrane modules. In this study, we present a novel and straightforward process for modifying stainless-steel supports to seed zeolite membrane layers. High-performance, b-oriented MFI zeolite membranes can be synthesized on these modified stainless-steel supports through scalable filtration seeding of MFI zeolite nanosheets followed by secondary growth. By employing a carefully designed pre-treatment procedure, we achieved the growth of well-intergrown, highly b-oriented MFI zeolite membranes on the modified stainless-steel support, establishing a robust interaction with the substrate. The membranes, fabricated through gel-free secondary growth of nanosheets deposited on a scalable stainless-steel support using this technique, demonstrate ultra-selective capabilities in separating para-xylene from ortho-xylene, with a high separation factor of 388.

Novel strengthening method of signal tower using prestressed CFRP plates: Concept and behavior

A novel prestressed carbon fiber reinforced polymer (CFRP) plate strengthening method for signal towers was proposed. The proposed strengthening system incorporates a circumferential anchorage system, a support system, a column system, and CFRP plates. These elements synergistically interact with the tower, forming a self-balancing system. This integrated system can provide exceptional flexural capacity and reduce the lateral displacement of the tower under wind load. To validate this novel method, a series of four static load tests were conducted. The results showed that the initial stiffness of the strengthened tower with CFRP plate prestresses of 0, 200, and 400 MPa increased by 71.0 %, 113.8 %, and 113.8 % compared with the unstrengthened tower, respectively. Moreover, the CFRP plate slacking occurred later for the strengthened tower with higher CFRP plate prestress, and the stiffness of the tower after the CFRP plate slacking kept increasing as CFRP plate prestress increases. The results indicate that the prestressed CFRP plate strengthening method effectively improved the behavior of the tower under wind load. Moreover, the finite element method (FEM) was utilized to analyze the influence of the ratio of the circumferential anchorage system height to tower height, the ratio of the support system height to tower height, the ratio of the column height to tower height, the ratio of steel support length to tower diameter, the elastic modulus of the CFRP plate and CFRP plate prestress on the strengthening effect. Finally, a strengthening procedure was proposed according to FEM results and sensitivity analysis. The analysis findings can serve as a guide for designing the strengthening system.

Effect of Steel Support Cross-Section and Preloaded Axial Force on the Stability of Deep Foundation Pits

Effect of Steel Support Cross-Section and Preloaded Axial Force on the Stability of Deep Foundation Pits

Seismic Behaviour of Steel Building with And Without Bracing System by Performance Point

Steel structures have been playing an important role in the construction industry in recent years. It is necessary to create a model that performs well under seismic loading. Seismic performance of multi-storey steel framed buildings is designed as per the provisions of the Indian Code (IS 800 -2007). The ductility of the structure can be increased by adding steel support to the structure. There are different types of support for retrofitting. X-brace, diagonal brace, V-shaped brace, inverted V-shaped brace etc. There are many ways to prepare steel supports such as: The frame of the building is designed with or without different types of connections such as diagonal, X-brace, V-brace and inverted V-brace, which will be considered in this study. The performance of each frame was examined by nonlinear static analysis (pushover analysis) using the ETABS-2021 software package. The comparison of braced and unbraced frames was based on the examination of base shear forces, hinge consequences and lateral displacements of different frames. Compare the response curves and performance points of different frames with and without support systems to know the relationship between the various frames involved.

Experimental study on the seismic performance of prestressed wood joints with buckling-restrained rods

Adding energy dissipaters to prestressed wood joints with reinforced beam-column interfaces is the main way to improve their seismic performance. In this paper, three quasistatic tests for beam-column edge joints with buckling-restrained rods (BRRs) were performed, and the effects of different reinforcements for beam-column interfaces and BRR connection methods on the stiffness, bearing capacity, energy dissipation, and self-centering performance of the joints were analysed. First, for BRRs connected with steel supports, the core member exhibited significant multi-wave deformation; for BRRs connected with steel pins, the slippage of the steel pins can easily lead to bending failure of the BRR end. Second, after adding BRRs, the bearing capacity of the joints increased by 24.8% on average, the final degradation rate of the secant stiffness decreased by 13.8% on average, and the equivalent viscous damping ratio at 0.03 rad drift increased by 17.3% on average. Third, compared with the joint reinforced by the combination of the U-shaped steel plate and screws, the skeleton curve of the joint reinforced by the combination of the flat steel plate and screws had little difference, but the final prestressing loss and residual drift were reduced by 14% and 74%, respectively. It was recommended to use the simpler reinforcement combining the flat steel plate and screws to improve construction efficiency. Finally, compared with steel pins, BRRs connected with steel supports were more conducive to improving the seismic performance of joints at large drifts. Among them, the equivalent viscous damping ratio increased by 29.3% on average. This study can give designers flexibility when selecting the interface reinforcements and BRR connection methods. These research results highlight the good seismic performance of prestressed wood joints with BRRs, which is conducive to further promoting the application of prestressed wood structures.

Bearing Steel Structures for Installation of Railway Strain Gauge Scales

Purpose. The main purpose of the publication is to compare the main technical and economic indicators of the two proposed structural variants of the support system for railway strain gauge scales for four-axle wide gauge railcars. This is due to the need to reconstruct and modernize the fixed assets of an industrial enterprise, in particular, to overhaul and replace old railway scales with modern electronic strain gauge scales. Also, the purpose of the work is related to the need to expand the range of railway cars for which the possibility of weighing is provided, including transport units of the foreign car fleet. Methodology. To achieve this goal, we analyzed the modern types of railroad cars for freight transportation, determined the main components of strain gauge scales for weighing the main types of cars, and developed a special support system to support the scale platform. The support system is provided in two design variants - with one spatial support frame and two separate flat support frames. Using the domestic design and computing complex SCAD, we built finite element models for both proposed design options. Based on the analysis of their stress-strain state, rational cross-sections were selected for each structural element, and the total mass was determined. Findings. A comparative analysis of the two developed structural solutions for the support system for modern railway strain gauges has revealed that the variant with two separate bearing frames has a lower weight by about 40 % compared to the variant with one spatial bearing frame. However, the manufacturability of its production is somewhat lower, since it involves 10 structural elements compared to 7 for variant No. 1. Originality. The numerical analysis made it possible to theoretically substantiate a more rational and efficient design solution for the support system for modern railway strain gauge scales. Practical value. A constructive variant of the steel support system has been developed and proposed for practical implementation, which is the most effective in terms of its technical and economic indicators for the existing conditions of an existing industrial enterprise. The developed design option was also coordinated with the project of major reconstruction of the building for weighing railroad cars.

Gradient failure mechanism and control technology of deep roadways under the action of deviatoric stress field

Deformation control of deep roadways is a major challenge for mine safety production. Taking a deep roadway with a burial depth of 965 m in a mine in North China as the engineering background, on-site investigation found that significant creep deformation occurred in the surrounding rock of the roadway. The original supporting U-shaped steel support failed due to insufficient supporting strength. The rock mass near the roadway experienced a transition from triaxial stress conditions to biaxial and even uniaxial stress states as a result of excavation and unloading, leading to a gradient stress distribution in the surrounding rock. From the perspective of the roadway's deviatoric stress field distribution, we investigated the gradient failure mechanism of the roadway and validated it through theoretical analysis and numerical simulations. The study found that the ratio of horizontal principal stress and vertical principal stress determines the distribution shape of the surrounding rock deviatoric stress field. The gradient distribution of the stress field in the roadway will cause time-related deformation of the roadway, which will lead to large deformation and failure of the roadway. Based on this, the control mechanism of roadway gradient failure was studied, and then a combined support technology of CFST supports with high bearing capacity was proposed.

Study on the Influence of the Performance Weakening of the Disconnectable Coupling (DC) Joint of Steel Support on the Retaining Structure of a Foundation Pit

In order to quantitatively study the influence of the weakening of the disconnectable coupling joint (DC joint) on the retaining structure, the pre-axial force retention performance of the steel support, the axial force of the steel support, the horizontal displacement of the diaphragm wall, and the ground settlement around the foundation pit were monitored during the construction of the foundation pit. The evolution process of the monitoring data was analyzed, and the corresponding numerical model verified by the monitoring data was established. The influence of the yield load of the DC joint, the initial compression stiffness, and the weakening of the pre-axial force on the stability of the retaining structure was studied by numerical simulation. The results show that the pre-axial force of steel support is only 67% of the design value when the soil below is not excavated within 24 h. The DC joint has a significant weakening effect on the steel support, which is unfavorable for the stability control of the foundation pit retaining structure. The pre-axial force and initial bending stiffness have a great influence on the stability of the retaining structure. When the yield load is not lower than that of the row piles, the DC joint has no effect on the stability of the retaining structure. This model can predict and analyze the deformation trend under different working conditions to a certain extent, providing certain reference value for safety plans during construction.

PUSHOVER ANALYSIS OF EARTHQUAKE RESISTANCE RCC STRUCTURE USING STAAD.PRO SOFTWARE

RCC structure has become crucial to the construction industry in recent decades. A structure must be designed with strong seismic performance in mind. A multi-story reinforced concrete building's seismic performance is planned in compliance with the current Indian code (IS 456 -2000). The study of each structural members performance is conducted using nonlinear static analysis. This paper study about a popular method to ascertain the performance level of a building is through pushover analysis, which yields results that indicate whether collapse occurs at the member or structure level. Performance-based design is used to evaluate the performance level of buildings subjected to earthquakes. Various approaches in nonlinear static analysis were developed to study the performance of a building. This assessment has taken into account a non-existing solid Rcc structure that is assumed to be located in Zone IV, as defined by IS 1893:2000, a classification of seismic zones in India. During the entire inquiry, brick work infills have been considered to be non-structural individuals. Systems for inelastic static static study include the Secant Method, the Displacement Coefficient Method, and the Capacity Spectrum Method. Pushover Analysis, a non-direct static approach, was used to examine the structure's weak points, building on static testing. The structure was recreated in SeismoStruct Version 5.2.2 using M20 cement and Fe415 steel support, as predicted in STAAD Pro v8i. After that, the research is carried out for 150% of the predetermined objective displacing for the structure to track individual yielding and the sufficiency of the core quality. The degree of damage suffered by the structure during the objective displacing is thought to represent the damage the structure would experience under configuration level ground shaking. Key Words: Pushover analysis, RCC structure, Pushover curve, drift velocity, STAAD.PRO, Earthquake structure.

Research and engineering practice of 70-m long-distanceaxial-force servo steel support technology

For deep excavation projects in areas with soft soil and a sensitive surrounding environment, an axial force servo steel support is usually adopted to control the deformation of retaining structures; however, the traditional axial force servo steel support can only be applied to deep excavations with a width of approximately 20 m owing to its technological limitations. In this study, considering the deep excavation project of Shanghai Xuhui Riverside Area A as an example, relevant technical research on a 70-m long-distance axial force servo steel support was conducted and the effect of this steel support in engineering practice was analyzed. Through the successful application of the project, the engineering safety reliability and deformation control effectiveness of the 70-m long-distance axial force servo steel support were verified, which can provide a reference for the design of similar projects.

Economic Study of Strengthening of Existing RCC Building

Many structures fail or deteriorate before completion of its intended life span due to poor quality of material used, lack of mix design, poor workmanship, attacked by environmental agencies, etc. Sometimes due to slenderness of column or less reinforcement provided than actual requirements, less depth/thickness provided in flexural members, etc. feels excessive vibration during walking on floor ultimately develops cracks. Strength of such structural elements can be found by using non-destructive tests like Rebound hammer test, ultrasonic pulse velocity test, etc. If strength of existing structural elements is less than desired strength then structural consultant suggested strengthening of structural elements. There are various methods used in strengthening of existing structural elements like pressure grouting, fibre wrapping, chemical treatment, structural steel support, jacketing, etc. But these techniques are very costly and need precise quality control activity. In the present of investigation, strengthening of beam and column elements of a building by ferrocement techniques and steel jacketing were carried out and cost and cost comparison and strength results before and after strengthening are presented. It is observed that the strength og structural by ferrocement technique is cost effective than steel jacketing technique. And also has increase in the strength of RCC elements

Investigation of a Cathodic Protection Configuration for the Steel Casing Pipes in Reinforced Concrete Bridge in the Niger Delta

This paper details the Design of a Cathodic Protection System on the steel casing pipes of the 60m reinforced concrete bridge project in the Niger Delta, Nigeria. Galvanic anode cathodic protection system was provided for the submerged steel support piles on the newly reinforced concrete bridge to ensure adequate corrosion protection of the structures. A total of fifty-six (56) Aluminum Anodes (32 kg) were used. Two of the Aluminum anodes were installed on each of the twenty-eight (28) steel casing piles. The anode installation was achieved by means of clamping at the predetermined water depth of 37.2 m with purpose made carbon steel clamps. The bonding of the anode to the pile structure to make electrical contact was achieved through welding of the pre-installed anode steel core extension bar against the steel pile at the water splash zone area of the river. A pre- and post-installation test and survey activities were conducted on each of the steel piles to ascertain the integrity of the installation and degree of corrosion protection of the steel casing piles. The field test and measurement results indicated mean values of open circuit potential of 0.600 Volts and polarized corrosion potential of 0.850 Volts. The recorded corrosion potential for the installed cathodic protection system confirmed adequate corrosion protection for ten (10) years from anode life for the steel casing supports of the 60 m reinforced concrete bridge.

Mechanism of bolt breakage in deep mining roadway under dynamic load and advanced strengthening support technology

To reveal the problem of local instability caused by bolt breakage and failure in deep mining roadway under impact dynamic loads, and explore strengthening support technologies that can reduce bolt breakage and improve the stability of roadway support bodies. This article adopts theoretical analysis, numerical simulation, and on-site industrial experiments to conduct research, investigate and obtain the fracture failure characteristics of bolt in deep mining roadway, quantitatively characterize the deformation pressure of roadway surrounding rock and dynamic load of overburden fracture, establish the mechanical criterion of bolt fracture, and analyze the influence law of different anchoring factors on bolt force under static load and dynamic and static load combination. The results show that when the anchor angle is different, the range under dynamic load increases by 169.3 % compared with static load, when the anchor length is different, the range increases by 863.3 % relatively, and the influence is significant; while the anchor support resistance increases by 11.6 % at different times, and the range decreases by 41.5 % at different pre-tightening torque. Then, based on this criterion, the influence law of bolt failure on the stability of surrounding rock is analyzed, and the optimal support scheme is obtained by simulation research, that is, bolt cable +U steel support scheme. After adopting this scheme for support, the deformation of surrounding rock is reduced by about 60 %, and the maximum concentrated stress of surrounding rock of roadway is reduced by 15.0 %. Based on this, the support parameters of the on-site roadway were optimized and a strengthening support scheme was determined, which includes “roof bolt surface support reinforcement + anchor cable combined with U-shaped steel deep reinforcement, and two strong bolts advanced reinforcement”. The on-site strengthening support practice showed that the bolt fracture rate was reduced by 87.3 %, the deformation of the surrounding rock was effectively controlled, and the stability was significantly improved.

Novel in-situ real-time line scan optical monitoring of wear and surface damage initiation in a laboratory twin disc test

A new optical monitoring system has been developed to photograph in-situ in real time the initiation of damage on the running surface of a rail steel twin-disc sample undergoing wear testing. The line-scan camera system has been demonstrated on the Sheffield University ROlling Sliding 2 (SUROS2) twin-disc machine. The results show the system can continuously track the development of wear flakes, with wear flake initiation and stabilisation of wear flake size observed without test interruption for the first time. Image analysis to quantify the total wear flake shadow pixel count showed a good correlation with the mass loss results, indicating the potential for the optical data to quantify rail steel wear without interruption to testing. Furthermore, in a water-lubricated test the new system enables observation of rolling contact fatigue (RCF) crack initiation through a water layer present on the specimens, without requiring test interruption. The improving knowledge of the wear and RCF performance of rail steels available from the new observation method can help improve understanding of steel performance and support to the selection of rail steel grades according to their performance.

PULL OUT TESTER EQUIPMENT

The strength and respectability of substantial sections in development projects are fundamental for guaranteeing underlying soundness and security. To survey the bond strength among support and cement in pieces, a take-out testing machine has been utilized. This examination explores the functional utilization of take-out testing to assess the bond strength of steel support inside substantial sections. The review frames the exploratory methodology, in which an exceptionally planned take out testing machine was utilized to expose tests of substantial sections to expanding pliable burdens. The power expected to start the draw out of support from the substantial framework was estimated and dissected. Results show that this system is a compelling method for evaluating the bond strength of chunks. The discoveries from the take out testing give significant experiences into the quality and dependability of substantial pieces utilized in development projects. Such testing helps with the ID of expected shortcomings, guaranteeing that sections fulfill or surpass primary guidelines. This exploration adds to upgrading the quality control and security estimates in the development business, at last working on the sturdiness and execution of substantial sections. Key Words: Bond strength , Bond slip

Analysis of Displacement Influence of Span of Prestressed Fish-Belly Beam on Foundation Pit Plane

As a new technology of antagonistic internal support, prestressed fish-bellied steel support system has been widely used in various foundation pit projects because of its advantages such as reutilization, effective displacement control and large mechanical operation space. But at present, the plane layout depends on experience, and has not yet formed a set of complete and reasonable plane layout methods. In the plane layout, the corner brace is arranged according to the condition of the plane stress balance of the corner brace, then the brace is arranged based on the corner brace balance theory, and finally the optimal span of the fish-belly beam is selected. The displacement diagram of supporting structure is obtained by using Midas/Gen with the span of fish-belly beam as the variable, the influence of the span of fish-belly beam on the horizontal displacement of foundation pit is analyzed, the relationship formula between the span of fish-belly beam and the size of foundation pit is obtained, and the plane layout method of prestressed fish-belly beam system is proposed.

Study on Influence of Tension Height of Steel Strand on Displacement of Foundation Pit Supported by Fish-bellied beams

The steel support system of prestressed fish-bellied beams can reliably control the deformation of foundation pit and provide open excavation space for foundation pit excavation, in which the triangle plate plays an important role in the fish-bellied beams system. But the deformation of the triangle plate and the steel strand is too large is a common problem in the foundation pit support, through the analysis of the stability of the triangle plate, it is found that the tension point height is an important factor leading to the deformation of too large. Through MIDAS/GEN analysis, it is found that the increase of the tension point height of the strand is conducive to the control of the displacement of the connecting part, and with the increase of the tension point of the strand, the anti-impact stability of the fish-bellied beams system is gradually enhanced. Therefore, by changing the tension height of the steel strand, the supporting system of the fish-bellied beams is optimized.

Offshore floating wind turbine foundation revolution enabled by fiber-reinforced polymer (FRP) reinforced cementitious materials

<p>Offshore floating wind turbines (OFWTs) are gaining popularity due to their superior wind energy capture and minimal visual impact. However, traditional steel support foundations for OFWTs are plagued by corrosion issues. This article proposes the use of Fiber-Reinforced Polymer (FRP) reinforced Ultra-High Performance Concrete (UHPC) composites, referred to as FRU composites, for OFWT foundations. Durability assessment of FRU plates under simulated marine environment is conducted based on accelerated aging tests on FRU plates. Scanning electron microscope (SEM) analyses are conducted to explore the fracture surface and interface between FRP and UHPC matrix. A series of tests are conducted and the test results of the FRU elements are summarized in this article. Strength design methodologies for FRU elements under various loadings are established based on summary of existing studies. Hydrodynamic analyses and comparative studies between FRU and steel OFWTs reveal that FRU OFWTs demonstrate improved stability and reduced motion responses under combined wind-wave-current loading conditions. The successful development of FRU composites is anticipated to revolutionize the OFWT industry by offering durable and cost-effective foundation options.</p>