Analytical‐numerical solution for stress distribution around tunnel reinforced by radial fully grouted rockbolts

Ranjbarnia, Masoud; Oreste, Pierpaolo; Fahimifar, Ahmad; Arya, Amir

doi:10.1002/nag.2517

Cited by 15 publications

(5 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Anchors as practical reinforcements are widely used in engineering constructions because of their reliable technology and good economic benefits [6][7][8]. However, the theoretical research on anchor system is relatively inadequate because it has a complex stress mechanism that involves many factors.…”

Section: State Of the Artmentioning

confidence: 99%

Analytical Calculation on the Load - Displacement Curve of Grouted Soil Anchors

Yang¹,

Chen²,

Zhang³

et al. 2018

JESTR

View full text Add to dashboard Cite

The load-displacement curve of anchors can be used as a basis for quality tests, and it is also important in the stability analysis of the combined supporting structure of anchors. Most of the existing analytical methods can only solve the partial pullout process of grouted soil anchors and obtain local load-displacement curves. To obtain a complete loaddisplacement curve, mechanical differential equations for the anchoring section in each stage were derived in this study based on a softening shear model of the anchor-soil interface and a load transfer model of the anchoring section. Combined with boundary conditions, the displacement, axial force, and shear stress distributions along the anchoring section and the analytical solutions for the load-displacement curve in the entire pullout process of anchors were obtained. The accuracy of the proposed method was verified by a pullout test on a foundation pit in Chongqing, China. Results show that a complete load-displacement curve is obtained with the proposed analytical method and a theoretical curve is consistent with a field pullout curve. The shear stress on the anchoring section is irregularly and non-uniformly distributed with a single peak. The load-displacement curve is influenced by the changes in parameters, such as anchorage length, anchorage radius, elastic modulus of the anchoring section, and residual shear coefficient. The present study accurately simulates the entire pullout process of anchors, determines their ultimate bearing capacity, obtains a complete load-displacement curve, and provides a theoretical basis for the quality evaluation and modelling analysis on grouted soil anchors.

show abstract

Section: State Of the Artmentioning

confidence: 99%

Analytical Calculation on the Load - Displacement Curve of Grouted Soil Anchors

Yang¹,

Chen²,

Zhang³

et al. 2018

JESTR

View full text Add to dashboard Cite

show abstract

“…Therefore, on the basis of Eqs. (4), (9), and (10) and the Hoek and Brown strength criterion, it is possible to write the minimum local safety factor inside the pillar with the following simple relation:…”

Section: ;Strmentioning

confidence: 99%

“…Nowadays, the area of in uence method cannot be used to dimension a rock pillar. Di erent methods, like three-dimensional numerical and analytical modelling [6][7][8][9], can be adopted to determine the stress strain state inside the pillar and, therefore, the local safety factors in the rock mass.…”

Section: Introductionmentioning

confidence: 99%

The rock pillar stress analysis in order to obtain an effective dimensioning and guarantee the mining void stability

2017

Self Cite

View full text Add to dashboard Cite

In the room and pillar mining method, dimensioning of the pillars is of fundamental importance. Nowadays, the area of in uence method is typically used for dimensioning of the pillars; however, over-dimensioning or critical stability conditions can happen in this method. A parametric analysis with three-dimensional numerical modelling was carried out to study the stress conditions of rock pillars in details. This helped to identify a critical point, where the minimum local safety factor was reached, at the corners of the pillar close to the roof of the mining room. Through the estimation of the major principal stress at the critical point, it was possible to evaluate the minimum local safety factor through the geometric and geomechanical parameters of the problem. The dimensioning of the pillars through the local safety factor at the critical point helps to avoid over-dimensioning and static problems, which can occur when simpli ed calculation methods are used. The use of the proposed gures can allow a fast pre-dimensioning of the pillars, leaving the more detailed numerical modelling only for the found geometric con guration.

show abstract

“…Wang et al believed that the intermediate principal stress was an important factor to determine the plastic zone; thus, the H-B strength criterion was modified by considering the intermediate principal stress, and the theoretical formula of the plastic zone radius of a rock tunnel was proposed [20]. Ranjbarnia et al developed a new analytical-numerical procedure based on the H-B strength criterion to provide the stresses and strains around a circular tunnel in rock masses exhibiting different stress-strain behaviours; a simple relationship was also presented to determine the closure of a circular tunnel in terms of the rock mass strength and tunnel depth [21]. Sharan compared the applicability of the M-C and H-B strength criteria in a rock tunnel, analysed the elastic-brittle-plastic behaviour of tunnel and evaluated the stress difference of the surrounding rock in a tunnel between the expansive and non-expansive rocks using a numerical method [22].…”

Section: Introductionmentioning

confidence: 99%

Study on Stress and Displacement of Axisymmetric Circular Loess Tunnel Surrounding Rock Based on Joint Strength

Bai

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

The development of an effective evaluation method suitable for loess-tunnel excavation is necessary to avoid the collapse accidents caused by tunnel excavation and any secondary disasters. Although the Fenner formulas and the modified Fenner formulas are widely used in tunnel engineering, a defect still exists in these formulas because the Mohr–Coulomb (M–C) criterion exaggerates the tensile strength of the surrounding rock of the loess tunnel. A newly modified Fenner formula was derived based on joint strength to overcome this deficiency. First, the expressions of stress and the radius of the plastic zone of the surrounding rock of the loess tunnel and the expressions of radial displacement were derived based on the stress-equilibrium equation of the axisymmetric plane and the joint strength. Then, the difference in the modified Fenner formulas based on the two kinds of strength criteria for the loess tunnel were compared. The results showed that the radius of the plastic zone and the radial displacement of the loess tunnel determined by the modified Fenner formula based on joint strength were larger than those determined by the modified Fenner formula based on M–C strength. However, the plastic stress of the plastic zone determined by the modified Fenner formula based on joint strength was smaller. The comparative analysis reveals that the modified Fenner formula based on joint strength can evaluate the stress and plastic-displacement field of the surrounding rock of a loess tunnel more reasonably.

show abstract

Analytical‐numerical solution for stress distribution around tunnel reinforced by radial fully grouted rockbolts

Cited by 15 publications

References 31 publications

Analytical Calculation on the Load - Displacement Curve of Grouted Soil Anchors

Analytical Calculation on the Load - Displacement Curve of Grouted Soil Anchors

The rock pillar stress analysis in order to obtain an effective dimensioning and guarantee the mining void stability

Study on Stress and Displacement of Axisymmetric Circular Loess Tunnel Surrounding Rock Based on Joint Strength

Contact Info

Product

Resources

About