scholarly journals Static Pull Testing of a New Type of Large Deformation Cable with Constant Resistance

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhigang Tao ◽  
Shihui Pang ◽  
Yijun Zhou ◽  
Haijiang Zhang ◽  
Yanyan Peng
Keyword(s):  
Large Deformation ◽  
Static Friction ◽  
Deformation Energy ◽  
Resistance Force ◽  
Constant Resistance ◽  
New Type ◽  
Field Static ◽  
Energy Absorbing ◽  
Pull Tests ◽  
Pull Testing

A new type of energy-absorbing cable, Constant-Resistance Large Deformation cable (CRLD cable) with three different specifications, has been recently developed and tested. An effective cable should occupy the ability of absorbing deformation energy from these geodisaster loads and additionally must be able to yield with the sliding mass movements and plastic deformation over large distances at high displacement rates. The new cable mainly consists of constant-resistance casing tube and frictional cone unit that transfers the load from the slope. When experiencing a static or dynamic load and especially the load exceeding the constant resistance force (CR-F, a static friction force derived from the movement of frictional cone unit in casing tube) of CRLD cable, the frictional cone unit will move in the casing tube along the axis and absorb deformation energy, accordingly. In order to assess the performance of three different specified cables in situ, a series of field static pull tests have been performed. The results showed that the first type of CRLD cable can yield 2000 mm displacement while acting 850 kN static pull load, which is superior to that of other two types, analyzing based on the length of the displacement and the level of static pull load.

scholarly journals A cable supporting test under impact loading based on 5G-IoT

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiaokun Sun ◽  
Zhaohua Li ◽  
Tao Hong
Keyword(s):  
Large Deformation ◽  
Impact Loading ◽  
Numerical Study ◽  
Deep Mining ◽  
Axial Forces ◽  
Constant Resistance ◽  
Released Energy ◽  
Reasonable Choice ◽  
Energy Absorbing ◽  
Seismic Magnitude

AbstractReliable supporting effect is of utmost important for the deep mining roadway to prevent the hazards during deep mining activities. Traditional supporting equipment are not satisfying in the absence of the energy-absorbing capacity, whereas the Constant-Resistance-Large-Deformation (CRLD) cable, which can endure a large deformation of 2 m and provide a constant resistance in the meantime, would be a reasonable choice. To verify the CRLD performance of the new cable and highlight its energy-absorbing capacity under impact loading, this paper designed an in situ blasting test in a discarded deep roadway, which is divided into four sections and reinforced by the traditional and CRLD cables, respectively. Firstly, a numerical study of the blasting testis is carried out, the CRLD cable element is proposed, based on the existing one of the FLAC3D software, and a static pullout test is simulated to verify the new element, the adapted impact loading is estimated and the dynamic calculation is performed. Furthermore, under the blasting, which releases the energy of the 1st seismic magnitude, the monitored axial forces of the cables are transmitted in real time using 5G-IoT, and the supporting effects of the two types of cables are compared. According to the numerical and experimental results, the CRLD cable is proven reliable to support the deep roadway, at least shocked by the released energy corresponding to the 1st seismic magnitude.

scholarly journals Real-time Remote Monitoring System Based on the Large Deformation Cable with Constant Resistance for Landslide Disaster and Its Application

2015 ◽  
Vol 9 (1) ◽  
pp. 504-609
Author(s):  
Zhigang Tao ◽  
Haipeng Li ◽  
Haijiang Zhang ◽  
Xiulian Zhang
Keyword(s):  
Real Time ◽  
Large Deformation ◽  
Remote Monitoring ◽  
Slip Surface ◽  
Water System ◽  
Remote Monitoring System ◽  
Constant Resistance ◽  
Monitoring And Forecasting ◽  
Energy Absorbing ◽  
Sliding Force

It is meaningful for researching on monitoring and forecasting technology of slope stability to prevent landslide disasters, especially in the water system fields. Based on the mechanical principle of interaction among sliding mass, sliding bed and monitoring cable, a new type of energy absorbing cable (called Large Deformation Cable with Constant Resistance) which can have 2000mm deformation with constant pull load of 850kN is developed. The mechanical principle of relative movement between sliding mass and sliding bed is proposed, and the multi-factor monitoring is transformed into single landslide mechanical monitoring. The relationship between sliding force of slope and pretightening force of monitoring cable is set up. According to the physical model experiment of landslide, the sliding force at the potential slip surface will change continually before the landslide. When the sliding force is greater than the shear resistance at the potential slip surface, the landslide will take place, which means the variation of sliding force at the potential slip surface will be ahead of displacement on the ground of slope. Consequently, monitoring the variation of sliding force at the potential slip surface is better than that of the displacement. Based on above principle and experiment, the system of real-time remote monitoring and forecasting for landslide disasters based on the large deformation cable with constant resistance is developed, which can realize the real-time remote monitoring warning of sliding force. Several landslides have been successfully predicted.

Anchoring effect and energy-absorbing support mechanism of large deformation bolt

2021 ◽  
Vol 28 (2) ◽  
pp. 572-581 ◽  
Author(s):  
Tong-bin Zhao ◽  
Ming-lu Xing ◽  
Wei-yao Guo ◽  
Cun-wen Wang ◽  
Bo Wang
Keyword(s):  
Large Deformation ◽  
Support Mechanism ◽  
Anchoring Effect ◽  
Energy Absorbing

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

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Xiaoming Sun ◽  
Bo Zhang ◽  
Li Gan ◽  
Zhigang Tao ◽  
Chengwei Zhao
Keyword(s):  
Large Deformation ◽  
Support System ◽  
Field Tests ◽  
Soft Rock ◽  
Internal Force ◽  
Surrounding Rock ◽  
Gansu Province ◽  
Tunnel Engineering ◽  
Anchor Cable ◽  
Constant Resistance

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.

scholarly journals Dynamic Compressive Behaviors of Two-Layer Graded Aluminum Foams under Blast Loading

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1445 ◽  
Author(s):  
Minzu Liang ◽  
Xiangyu Li ◽  
Yuliang Lin ◽  
Kefan Zhang ◽  
Fangyun Lu
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Blast Resistance ◽  
Blast Loading ◽  
Deformation Energy ◽  
Aluminum Foams ◽  
Conflicting Objectives ◽  
Energy Dissipated ◽  
Transmitted Impulse ◽  
Energy Absorbing

Experimental and numerical analyses were carried out to reveal the behaviors of two-layer graded aluminum foam materials for their dynamic compaction under blast loading. Blast experiments were conducted to investigate the deformation and densification wave formation of two-layer graded foams with positive and negative gradients. The shape of the stress waveform changed during the propagation process, and the time of edge rising was extended. Finite element models of two-layer graded aluminum foam were developed using the periodic Voronoi technique. Numerical analysis was performed to simulate deformation, energy absorption, and transmitted impulse of the two-layer graded aluminum foams by the software ABAQUS/Explicit. The deformation patterns were presented to provide insights into the influences of the foam gradient on compaction wave mechanisms. Results showed that the densification wave occurred at the blast end and then gradually propagated to the distal end for the positive gradient; however, compaction waves simultaneously formed in both layers and propagated to the distal end in the same direction for the negative gradient. The energy absorption and impulse transfer were examined to capture the effect of the blast pressure and the material gradient. The greater the foam gradient, the more energy dissipated and the more impulse transmitted. The absorbed energy and transferred impulse are conflicting objectives for the blast resistance capability of aluminum foam materials with different gradient distributions. The results could help in understanding the performance and mechanisms of two-layer graded aluminum foam materials under blast loading and provide a guideline for effective design of energy-absorbing materials and structures.

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