Cable Support System Research Articles

Seismic performance of pentagonal type aluminum alloy suspen-dome structure with large opening

Prestressing technology is an effective way to enhance the mechanical properties of space structures. In view of this, a new pentagonal type aluminum alloy suspen-dome structure with large opening is proposed in this paper by introducing the lower cable support system into the aluminium alloy single-layer reticulated shell structure. The seismic performance of this new structure is investigated using time-procedure analysis. Firstly, the effects of rise-span ratio, thickness-span ratio, prestressing level, horizontal radius factor for lower chord nodes and roof loading on the free vibration characteristics of the structure with different supporting stiffness are investigated. The distributions of internal forces and displacements of members of overall structure considering lower support and roof structure only are analyzed. Subsequently, the dynamic response of the structure under seismic combinations of different dimensions and directions is investigated, and reasonable combinations that should be considered for simplified analyses are derived. Furthermore, seismic internal force coefficients are introduced to assess the degree of seismic effects on various types of members. On this basis, parametric analysis of the seismic performance of the structural performance is conducted and quantitative assessment of the sensitivity of the parameters is carried out. Additionally, the free vibration characteristics and dynamic performance of steel and aluminium suspen-dome are compared. The results show that considering the supporting structure weakens the structural stiffness while increasing the structural dynamic response; reasonable values of key parameters in the seismic design of the structure are obtained; and the rise-span ratio and thickness-span ratio are important influencing factors of the seismic performance of the structure. Besides, the internal forces of members in aluminium alloy suspen-dome are less affected by seismic effects than those in steel suspen-dome, and the new structure has good seismic performance.

Exploring the feasibility of prestressed anchor cables as an alternative to temporary support in the excavation of super-large-span tunnel

AbstractExcavating super-large-span tunnels in soft rock masses presents significant challenges. To ensure safety, the sequential excavation method is commonly adopted. It utilizes internal temporary supports to spatially partition the tunnel face and divide the excavation into multiple stages. However, these internal supports generally impose spatial constraints, limiting the use of large-scale excavation equipment and reducing construction efficiency. To address this constraint, this study adopts the “Shed-frame” principle to explore the feasibility of an innovative support system, which aims to replace internal supports with prestressed anchor cables and thus provide a more spacious working space with fewer internal obstructions. To evaluate its effectiveness, a field case involving the excavation of a 24-m span tunnel in soft rock is presented, and an analysis of extensive field data is conducted to study the deformation characteristics of the surrounding rock and the mechanical behavior of the support system. The results revealed that prestressed anchor cables integrated the initial support with the shed, creating an effective “shed-frame” system, which successively maintained tunnel deformation and frame stress levels within safe regulatory bounds. Moreover, the prestressed anchor cables bolstered the surrounding rock effectively and reduced the excavation-induced disturbance zone significantly. In summary, the proposed support system balances construction efficiency and safety. These field experiences may offer valuable insights into the popularization and further development of prestressed anchor cable support systems.

Shaking table test on anti-seismic characteristics of NPR anchor cable support system for tunnel crossing faults

Shaking table test on anti-seismic characteristics of NPR anchor cable support system for tunnel crossing faults

Green HRM In Improving Employee Performance By Mediating Role Of Green OCB And Green Behavior: Study On Manufacturing Companies In Singapore

This study examined the effect of green human resource management (GHRM) and organizational performance on Singapore's ELPRO Steel Conduit and Cable Support System Manufacturing Industry. This study introduced Green Behavior and Green OCB (Organizational Citizen Behavior) as mediating variables. This study uses a quantitative method. Data analysis used Partial Least Square (PLS) with smart-PLS3 software. The study population was Blue Pearls Pte Ltd Manufacturing Industry, Singapore's ELPRO steel conduit and cable support employees, with 106 respondents using the census sample method. The results showed that all the hypotheses tested were accepted. GHRM significantly impacts employee performance through the dominant factor of employee involvement in environmentally friendly practices. Meanwhile, Green Behavior and Green OCB can indirectly mediate GHRM on employee performance. The results of this research can provide insights for organizational to develop policies, programs and practices that encourage the adoption of GHRM, green Behavior and green OCB of employees and improve employee performance in their organization.

Impact of Continuous Cable-Strut Joints on the Anti-Progressive-Collapse Performance of Suspended-Dome Structures

In suspended-dome structures, cable-strut joints can be categorized into discontinuous joints and continuous joints. In calculations, the discontinuous joints can be treated as hinge joints. However, in the event of a cable breakage, the continuous joints might experience slip and detachment phenomena. Simplifying continuous cable-strut joints as hinge joints for calculation purposes can result in a significant discrepancy from the actual load-bearing state of the continuous joints. In fact, under the scenario of cable rupture, the continuous cable-strut joints might undergo slip and detachment. This could influence the formation of new tension paths within the cable support system, thereby affecting the anti-collapse performance of the suspended-dome structure. Therefore, this paper investigates the influence of the slippage and detachment of continuous cable-strut joints on the anti-progressive collapse performance of suspended-dome structures through joint tests, numerical simulations, and theoretical analyses. Firstly, two cable-strut joint test models were constructed. Apart from the difference that one uses a discontinuous cable-strut joint and the other a continuous cable-strut joint, all other conditions were kept identical. Research was conducted on the hoop cable failure test. The results indicate that the slippage and detachment of continuous joints hinder the formation of new tension paths in the lower cable-strut system. Structures using continuous cable-strut joints have lower anti-collapse capabilities compared to those using discontinuous cable-strut joints. Secondly, a simplified numerical simulation algorithm for cable-strut joints’ slippage and detachment is proposed. This algorithm only considers the support of struts to the upper structure and uses an Abaqus subroutine to achieve an equivalent simulation of the slippage and detachment phenomena of continuous joints during the finite element computation process. Then, using this algorithm, a progressive collapse analysis of suspended domes using continuous cable-strut joints was carried out. It was found that for suspended domes with continuous cable-strut joints, the slippage and detachment of the cable-strut joints are extremely detrimental to forming new tension paths, making the structure more susceptible to a progressive collapse. Lastly, using the resistance index, a quantitative analysis was conducted on the anti-collapse carrying capacity of suspended domes using both continuous and discontinuous cable-strut joints.

Field test and numerical simulation of initial support effect of negative Poisson's ratio anchor cable under strong impact and vibration

Bolt/cable support technology is widely used in the rock engineering protection field to limit large deformations of surrounding rocks, improve the anti-explosion and anti-impact mechanical properties of engineering rock mass, and increase stability and safety. The underground protective cavern suffers significant damage due to the powerful impact produced by the explosion. This paper studies the macro static and dynamic mechanical properties of the negative Poisson's ratio (NPR) constant resistance and large deformation anchor cable. In addition, an in-situ blasting test scheme is proposed to simulate the approximate plane wave generated by a nuclear explosion in the field. Hence, the anti-explosion and anti-impact properties of the NPR anchor cable support system and failure mode of ternary structure (rod body, anchor body, and rock mass) under explosion influence can be obtained. Finally, numerical modeling is utilized to validate the NPR anchor cable support and PR anchor bolt support under the high vibration condition with the same blasting equivalent. The findings showed that the cavern supported by the NPR anchor cable revealed better overall stability under strong impact and vibration than the PR anchor bolt.

Numerical modelling and field monitoring study on large-span tunnelling using pretensioned bolt–cable combined support system

This study focused on a new support method, a pretensioned bolt–cable combined support system, for large-span tunnelling. The Badaling tunnel is a high-speed railway station tunnel that has a span of 32.7 m, a cross-sectional area of 494 m2, and a maximum depth of 102 m. The super large cross-section and unfavorable geological conditions around the tunnel resulted in considerable difficulties for tunnel construction. Because this tunnel was successfully excavated using the pretensioned bolt–cable support, the mechanical characteristics of this new support system are analyzed in this study. First, the necessity of a bolt–cable support for large-span tunnelling was analyzed using a numerical model. The deformation characteristics of rock mass in the large-span tunnel are discussed based on the modelling results of the tunnelling process. Second, based on field monitoring results, the mechanical behaviors of pretensioned rock bolts and anchor cables were analyzed. The anchoring forces of the rock bolts and anchor cables were determined by the pretension forces, loss of pretension forces, and passive support effects. The development of the anchoring force can be divided into three phases: rapid loss of the pretension force, a fluctuation phase, and a stable phase. Finally, The loading effect and mechanical responses of the primary lining were analyzed according to the monitoring results of the primary lining, which indicated that the rock mass was effectively reinforced by the pretensioned bolt–cable system and that the primary lining was safe.

Semi-analytical solution for static and quasi-static analysis of an inextensible cable

The static and quasi-static analysis of cable structure and cable-driven systems is of significant interest to the researchers. In this paper, a semi-analytical solution for static equilibrium analysis of an inextensible cable is developed to know its initial configuration and tension. The analytical expression for the static equilibrium configuration of a cable, fixed at the two ends is generally available in the literature in terms of unknown reactions at the boundary nodes. Conventionally, researchers use numerical methods to solve for those unknown reactions at the boundary nodes, where a solution is sensitive to the initial guess. The proposed semi-analytical solution avoids such difficulty faced by an analyst or a designer of cable systems. The results obtained here were validated with a numerical solution for the static profile and cable tension. For the quasi-static analysis, these numerical methods are not suitable to compute the cable tension and its equilibrium profile due to the dependency of the solution on the initial guess and computation cost. To illustrate the need for a semi-analytical solution, the design problem for a cable support system and quasi-static analysis of an underwater tether connected between parent ship and a remotely operated vehicle (ROV) are presented. For the quasi-static analysis of the underwater tether, the proposed results are compared with those using the Newton-Raphson method in terms of computational cost and accuracy. In addition, guidelines are provided in this paper to choose an initial guess for the numerical approach so that a solution would be converged much faster.

On the Relation between Strength and Stiffness of Cable Tray

In order to realize the optimal design of the cable supporting system for the purpose of material saving and energy saving and green manufacturing, the strength-stiffness ratio is proposed in the paper in nondimensional form, which defines quantitatively the relation between the static load strength and stiffness of the cable tray. On the premise of ensuring service safety, the correlation between the strength and stiffness of the cable tray under static load is discussed extensively through the theoretical analysis of the mechanical model. The weakest link in the carrying capacity of the cable tray as well as the issue that needs to pay attention is proposed in the process of design and the test of the cable tray. A reasonable strength-stiffness ratio will help to make full use of the potential of material strengths. The value of the strength-stiffness ratio is obtainable by means of the finite element method or by the loading test of the cable tray. It is shown through the analysis that the value of the strength-stiffness ratio being setting in the range close to but less than 1 will make comparatively reasonable material utilization and will help the deflection test going smoothly to obtain a relatively safer allowable working load for the cable tray.

Study on Surrounding Rock Deformation Mechanism and Control of Roadway with Large Section and Extra-Thick Top Coal

In order to solve the problem of safe and rapid excavation and support of roadway with large section and extra-thick top coal under complex geological conditions, the deformation mechanism and control of roadway are analyzed by means of field investigation, numerical simulation, theoretical analysis, and field practice, taking the 2203 transportation roadway of a mine in Shanxi Province as the engineering background. The results show the following: (1) the concentration of normal tensile stress in the middle of large-span roadway roof and end shear stress is significant, which may easily lead to the separation of roof and the extrusion deformation of surrounding rock; (2) the surface shear failure depth of the roadway side is large, and the insufficient length of the bolt, the small density of the protective side, and the insufficient support strength are easy to cause the bulge and splitting of the coal wall; (3) roof joints and fractures are developed, and the dirt band of different thickness occurs, so it is easy for the roof separation and the anchor solids to cut down along the weak surface of the dirt band; (4) the geological structure produces horizontal movement of surrounding rock, which easily leads to poor supporting effect of roadway roof and material deformation and failure. Finally, a safe and economic comprehensive support system of “high-strength, high-resistance, and high-prestressed anchor cable support system + high-strength support of the two sides roadway + U-shaped anchor cable combined truss” is proposed, and the control mechanism is explained and applied successfully in the field.

Design optimization of the soil nail wall-retaining pile-anchor cable supporting system in a large-scale deep foundation pit

In the recent times, many studies have been devoted toward rectangular excavations but only a few studies have considered the “corner effect” in the optimized design of soil nail wall-retaining pile-anchor cable supporting systems, especially in large-scale deep foundation pit environments excavated by the central-island technique. Corner effect not only increases the construction costs but also may pose a risk to the safety and stability of such pits. In this paper, changes in the lateral displacement of retaining pile, soil at 1 m away from the foundation pit, crown beam, and the settlement of ground surface and surrounding buildings were extensively investigated based on the field measurements and numerical simulations of a large-scale deep foundation pit in Gaoxin zone, Xi’an, China. In addition, the supporting structure was optimized by considering the lateral influence zone of the corner effect. The optimization scheme proposed in this study not only satisfies the safety requirements of foundation pit supports, but also reduces the construction costs.

Research on Full-Section Anchor Cable and C-Shaped Tube Support System of Deep Layer Roadway

Deep roadway deformation due to soft rock, rock dip, and horizontal tectonic stress is uneven and asymmetrical primarily in large loose zones. Traditional anchor support is influenced by the yield strength and shear strength of the anchors and has a limited prestress capacity or shear resistance. When the roadway roof is laminated rock or when the roadway passes through layered rock or rock interfaces, interlayer sliding commonly occurs, which can easily lead to anchor cables being sheared off. The tape tunnel in the Zhengling Mine passes through several rock strata and requires anchors to achieve a high shear resistance and prestress. To solve these problems, an anchor cable and C-shaped tube that can bear lateral shear forces were developed, and a full-section anchor cable and C-shaped tube support system were created based on extruded arch theory. Numerical results from FLAC3D show that the new scheme effectively controls surface convergence and plastic zone extension. Field tests have demonstrated that the amount of surface displacement was at least 42% smaller in the new support scheme. The extruded arch formed by the highly prestressed anchor cable and concrete spray layer can effectively control the bulking load within the loose zone, and the ACC effectively resists interlayer shear.

Research on the full-section anchor cable and C-shaped tube support system of mining roadway in island coal faces

ABSTRACT Anchor cables often break in various forms. Tensile failure can be resisted by using high-strength materials, while there is no good solution for shear failure. A new supporting structure called Anchor Cable and C-shaped tube that can bear the transverse shear force was invented and a preliminary introduction to the mechanism of the structure is given. Field investigations and in-situ stress tests were carried out on the panel 3210 in the Nanguan Mine. The failure modes of the surrounding rock and cables and the in-situ stress test results show that the working face is obviously affected by the horizontal stress. Thus, a new full-section anchor cable and C-shaped tube support scheme were proposed. The results of FLAC3D show that the new scheme is excellent in controlling the surface convergence and plastic zone extension. The rationality of the scheme was verified by two-and-a-half months of monitoring. Compared with the original scheme, the amount of surface displacement was at least 20% smaller, and the time for the displacement to reach equilibrium was at least 27.4% shorter. The surface of the roadway is flat without supporting material damaging. The new scheme is worth popularizing in similar working conditions.

Research and Performance Test of New Full‐Length Anchorage Material

It is difficult to support roadway with anchor cable in view of impact tendency in impinging liability roadway; a new material of inorganic and high‐performance full‐length anchoring material for anchoring cable is developed by adding several modifiers with ultrafine cement as the main material. The purpose is to improve the mechanical properties and durability of cement‐based materials, improve the coordination of anchor cable support system, and ensure the stability of surrounding rock of mining roadway. The new full‐length anchoring material is developed by optimizing the proportion of different components of the material, and the mechanical properties of the new material were studied. The anchoring force of resin anchoring agent, ordinary Portland cement, blank ultrafine cement, and new full‐length anchoring material are tested. Based on SEM microscopic characterization, the fracture types and failure characteristics of resin anchoring agent and full‐length anchoring material are researched. The results show that the optimal content of each component of the new inorganic high‐performance full‐length anchorage material is as follows: the content of component A is 15%, the content of component B is 3%, the content of component C is 0.2%, the content of component D is 1%, and the content of component E is 1%; the tensile test shows that the full‐length anchoring material has good bonding property, high anchoring strength, strong stability, and good rock coupling. SEM microstructure and morphology analysis have showed that the new anchorage materials can fully hydrate each other, resulting in a relatively dense stone body. The new full‐length anchoring material can effectively improve the anchoring force and improve the stability of the anchor cable and has significant performance advantages and good engineering applicability, and it has the advantages of lower cost and safer to use. The new material is a very good supporting material for roadway.

Exact dynamic analysis of multi-segment cable systems

Cable-supported structure is a common system widely used in engineering, with the rapid development of the infrastructure and transportation industry, its structural form has become more and more complicated. Multi-segment cable system, which consists of a suspension cable and several lateral supports, such as the cable-damper system, the main cable of a suspension bridge, etc., is one of the important cable support systems. Due to the low structural rigidity and damping, its dynamic problems have always been the focus of engineering. To obtain a more general conclusion, a unified dynamic model considering the effect of cable sag, additional cable force, flexural stiffness, and the support stiffness of lateral components are considered in this paper for the first time. However, the exact analysis of this model is difficult, in view of this, the dynamic stiffness method is employed in this paper to investigate the dynamic characteristic of the multi-segment cable system. The accuracy of the proposed method is verified by comparing with finite element solutions and experimental results. Results show that the position of lateral supports has a strong coupling effect and influence the lower-order mode more significantly than higher-order modes, and the maximum frequency value can be reached by installing the supports equidistantly.

Experimental and theoretical study on cable-supporting system

Suspension type cable system is an important type of cable bearing system, its dynamic problems have always been the key to the structural design, health monitoring, and vibration control. In view of this, an exact dynamic analysis method for suspension type cables is proposed by the author. The dynamic characteristic of the suspension cable system is studied by a full-scale cable test. By comparing with experimental results and finite element solutions, the accuracy and universality of the proposed method are verified. The results show that the calculation result agrees well with the measured results, and the maximum relative error of each condition is basically no more than 2%. Through parameter identification, the bending stiffness, cable force, and the installation position of the weights are identified and corrected, and the calculation errors after parameter identification are controlled within 1%, which significantly improves the calculation accuracy and further verifies the accuracy of the proposed method.

Deviatoric Stress Evolution Laws and Control in Surrounding Rock of Soft Coal and Soft Roof Roadway under Intense Mining Conditions

Aiming at the problem of large deformation and instability failure and its control of soft coal and soft roof roadway under intense mining, laboratory experiments, theoretical calculations, Flac3D numerical simulation, borehole peeping, and pressure observation were used to study the deflection characteristics of the deviatoric stress of the gas tailgate and the distribution and failure characteristics of the plastic zone in the mining face considering the strain softening characteristics of the roof and coal of roadway, and then the truss anchor cable‐control technology is proposed. The results show the following: (1) The intense mining influence on the working face will deflect the peak deviatoric stress zone (PDSZ) of the surrounding rock of the gas tailgate. The influence distance of PDSZ is about 20 m in advance and 60 m in lag; the PDSZ at the gob side of the roadway is located in the range of 3–5.5 m from the surface of the coal pillar, while the coal wall side is mainly located in the range of 3–4.5 m at the shoulder corner and bottom corner of the solid coal. (2) The intense mining in the working face caused the nonuniform expansion of the surrounding rock plastic area of the gas tailgate. The two shoulder angles of the roadway and the bottom of the coal pillar have the largest damage range, and the maximum damage location is the side angle of the coal pillar (5 m). Angle and bottom angle of coal pillar are the key points of support control. (3) The plastic failure line of the surrounding rock of the gas tailgate is always between the inner and outer contours of the PDSZ, and the rock mass in the PDSZ is in a stable and unstable transition state, so the range of anchor cable support should be cross plastic failure line. (4) The theoretical calculations and numerical simulation results agree well with the drilling peep results. Based on the deflection law of the PDSZ and the expansion characteristics of the plastic zone, a truss anchor cable supporting system with integrated locking and large‐scale support function is proposed to jointly control the roof and the two sides, which effectively solves the problem of weak surrounding rock roadway under severe mining deformation control problems realizing safety and efficient production in coal mines under intense mining.

Under water glued stud bonding fasteners for offshore structures

The installation of offshore wind turbines has achieved rapid and substantial progress worldwide and further increase is predicted by enhanced technologies that will reduce costs and increase service time. Secondary structures applied to the primary structure, as the transition piece of a monopole, can be e.g. cable support, boat landing or anode systems. These structures are often welded, which leads to problematic notch effects and hydrogen embrittlement, especially for underwater applications. Also the handling of technical equipment as power current or artificial housings for scuba divers for underwater welding is challenging. Adhesive bonding will lead to cost reduction as the mentioned negative aspects can be avoided. The corrosion protection coating and the primary structure will no longer be damaged and therefore do not need a subsequent coating. This article focuses on the area which is permanently exposed to water. A critical point is how the capability to form adhesion and cohesion, will be influenced by the application process under water. Therefore, stud bonding fasteners are designed that enable the injection of adhesive to the bonding area under water. The load capacities for different adhesives, surface pre-treatments and the degradation by exposure to artificial sea water were investigated. Adhesion was achieved with two different adhesives, which were able to cure and realize reasonable strength under water. Furthermore, two selected coating systems were able to improve the performance of the adhesive bond.

Stability Analyses and Cable Bolt Support Design for A Deep Large-Span Stope at the Hongtoushan Mine, China

This study presents stability analyses and a cable bolt support design for a typical deep large-span stope (1-1# stope) at the Hongtoushan mine in China, using an integrated empirical and numerical method. Detailed field work including quantification of joint distribution and surface quality, along with laboratory test on intact rock samples, were performed to obtain the geotechnical properties of rock masses. The rock mass of the 1-1# stope was characterized by rock mass rating (RMR), rock mass quality (Q), and geological strength index (GSI), and then the modulus, peak strength, cohesive strength, and internal friction angle of the rock mass were estimated. The stability of the stope was then evaluated by empirical (RMR, stability graph) and numerical approaches (limit equilibrium analyses with UNWEDGE and stress-strain analyses with FLAC3D), considering of the effects of rock mass quality, induced stress, and large-span. A cable bolt support system obtained from the empirical method, was then further analyzed using the FLAC3D and UNWEDGE codes. The results show that the maximum plastic zone thickness and vertical displacement at the stope roof decrease significantly and the safety factor of the unstable wedge block increases significantly after installing the cable bolt support systems recommended by the empirical method. Therefore, it is suggested that an integrated empirical and numerical method is used to obtain quantitative stability assessment and optimum cable bolt support design for deep large-span stope roofs.

Application of Constant Resistance and Large Deformation Anchor Cable in Soft Rock Highway Tunnel

Muzhailing Highway Extra‐long Tunnel in Lanzhou, Gansu Province, China, belongs to the soft rock tunnel in the extremely high geostress area. During the construction process, large deformation of the soft rock occurred frequently. Taking the no. 2 inclined shaft of Muzhailing tunnel as the research object, an NPR (negative Poisson’s ratio) constant resistance and large deformation anchor cable support system based on high prestress force, constant resistance, and releasing surrounding rock pressure was proposed. The characteristics of the surrounding rock under the steel arch support and NPR anchor cable support were compared and analyzed by using 3DEC software. A series of field tests were conducted in the no. 2 inclined shaft, and the rock strength, displacement of the surrounding rock, deep displacement of the surrounding rock, internal force of steel arch, and axial force of anchor cable were measured to study the application effect of the NPR anchor cable support system in tunnel engineering. Moreover, the 3DEC numerical simulation results were compared with the field test results. The research results show that the application of NPR constant resistance and large deformation anchor cable support system in tunnel engineering has achieved good results, and it plays a significant role in controlling the large deformation of the tunnel surrounding rock.