Anchor Tension Research Articles

Study of the interaction between roof bolting of the output and a breed array inclined to creep

The basic equations of the theory of linear hereditary creep are considered. An algorithm for determining the value of the anchor tension as a result of deformation of rocks in the bottom-hole zone of the barrel is presented. The area of the scope of roof bolting trunks in various breeds is defined.

Design of anchor reinforcement for seismic tension loads

This paper presents a study of cast-in anchors in reinforced concrete subjected to both monotonic and cyclic tension. Laboratory tests using 25 mm [1 in.] diameter anchor bolts showed that the code-conforming anchor reinforcement may not ensure anchor steel failure though it effectively prevented concrete breakout. Based on the observations and other tests in the literature, recommendations for the design of anchor tension reinforcement were proposed, which consists of (1) load-carrying reinforcement in the direction of the anchors; (2) crack-controlling reinforcement in all directions that have a limited edge distance; and (3) local confining reinforcement near the anchor head if side-face blowout may control the failure. The proposed anchor reinforcement was proven effective using additional laboratory tests. Further studies are needed to verify the reinforcement design for anchor connections.

Study on Ultimate Pullout Force of Grouting Anchors of the Anchor-Pull Retaining Wall

Determination of the grouting anchor pullout force is a key step during the design of anchor-pull retaining wall, but it is mostly determined relied on empirical formula at present, and the rationality and the safety cannot be effectively guaranteed. Based on the engineering case of the gravity retaining wall of Qinglin Freeway, the model test was designed, and combined with the results of the ABAQUS finite element numerical analysis, it was analyzed that how the anchor axial pulling force distributes. The results showed that the force of the anchor near the wall bolt was large and which far from the wall was small and the ultimate pullout force was proportional to the length, diameter and shear strength. When the end tension of the anchor was small, the top load played a leading role on the anchor tension. This conclusion confirmed the calculation formula of ultimate pullout force was and provided a theoretical basis for anchor-pull retaining wall design and calculation.

Stability Calculation Method of Slope Reinforced by Prestressed Anchor in Process of Excavation

This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical.

Model Tests on Force Characteristics of Reinforced Retaining Wall

The recent research and development of the reinforced retaining wall is composed of cantilevered reinforced concrete retaining walls which symmetric set on both sides of subgrade and through roadbed width of counter-pulled anchors. The prestressing force can be applied on anchors.The retaining wall has the advantange of high safety, lateral small deformation , wide applicable range and low requirements for the foundation bearing capacity. But due to the lateral restraint of bolt, the soil pressure distributions of retaining wall change a lot. The change will have a significant impact on structures. In order to reveal the reinforced soil retaining wall pressure distributions, laboratory model test was done. The monitoring instruments such as earth pressure cells, anchor rope dynamometers and dial indicators were installed. Research and analysis on the loading process reinforced type soil retaining wall under soil pressure, the lateral earth pressure and anchor rope tension change rule were researched and analysed. The experimental results showed that with the increasing of filling soil height, the retaining wall had a tendency to tilt outward. The basolateral external pressure is larger than the inside pressure. At the same time, anchor tension increased as the top loading increased. Lateral earth pressure distribution is parabolic. Soil pressure around the anchor is larger than other area, the soil arch effect is significant.

Model Test of Mechanical Characteristics of Cantilever Retaining Wall with Mutual Anchor

In order to analysis force characteristics and changes of the anchor tension during the process of filling soil of the pull cantilever retaining wall, a model test is designed for research. The test mainly monitors basal earth pressure, lateral earth pressure of the retaining wall, anchor shaft force, lateral displacement of the retaining wall.

Semi-analytical quasi-static formulation for three-dimensional partially grounded mooring system problems

A semi-analytical quasi-static formulation based on the catenary approach capable of solving three-dimensional partially grounded and fully suspended multi-leg mooring-system problems is presented in this paper. The advantage of the present formulation is that only a compact governing vector equation, derived in terms of grounded cable length and anchor tension vector, need to be solved for each mooring cable to determine its grounded and suspended body response, and only a small number of discrete segments are needed to predict its behaviour accurately due to its inherent slope continuity. In addition, it is capable of handling arbitrarily inclined seabed interaction effects, varying cross-sectional and material properties as well as external attachment objects. The generality of the present formulation allows quick parametric analysis of different forms of multi-leg mooring system configurations as well as different types of flexible riser systems to be carried out.

Computation of Cutting Lengths of Guys

A method is presented for computing the cutting lengths of cable segments used as guys for antennas and transmission towers. The analysis takes into account both concentrated and distributed loading. An iterative computation procedure is employed whereby the length of the bottom cable segment and the angle of inclination of the anchor tension are initially assumed. The equations of equilibrium and compatibility are applied to each element of the assembly in a recurrent manner. The procedure is terminated when the coordinates of the uppermost joint of the guy are within a prescribed tolerance to those of the tower pin. A typical example is presented.