Showing papers on "Barrel vault published in 2013"

Tunnel vault cavity pumping backfill construction method

Abstract: The invention provides a tunnel vault cavity pumping backfill construction method. Firstly, a plurality of steel pipes or anchor rods are inserted into front soft and weak surrounding rock along the peripheral edges of a back supported steel arch support, the steel pipes or the anchor rods are used for forming an arch-shaped forepoling simple support structure with the back profile steel arch support as a supporting point, at least two steel pipes are pre-fixed in the middle of the simple support structure to be as a backfill concrete pumping pipe, then a layer of cover plates are paved on the top face of the simple support structure, a layer of fast setting concrete is spayed upwards with the simple support structure as a framework, an upper cavity is sealed, and after the sprayed sealing concrete is set, backfill concrete with preset thickness is pumped to the top face of the simple support structure through the pumping pipe.

Optimal design of single-layer barrel vault frames using improved magnetic charged system search

Abstract: The objective of this paper is to present an optimal design for single-layer barrel vault frames via improved magnetic charged system search (IMCSS) and open application programming interface (OAPI). The IMCSS algorithm is utilized as the optimization algorithm and the OAPI is used as an interface tool between analysis software and the programming language. In the proposed algorithm, magnetic charged system search (MCSS) and improved harmony search (IHS) are utilized to achieve a good convergence and good solutions especially in final iterations. The results confirm the efficiency of OAPI as a powerful interface tool in the analysis process of barrel vault structures and also the ability of IMCSS algorithm in fast convergence and achieving optimal results.

Non-linear stability analysis of a hybrid barrel vault roof

Abstract: This paper focuses on the buckling capacity of a hybrid grid shell. The eigenvalue buckling, geometrical non-linear elastic buckling and elasto-plastic buckling analyses of the hybrid structure were carried out. Then the influences of the shape and scale of imperfections on the elasto-plastic buckling loads were discussed. Also, the effects of different structural parameters, such as the rise-to-span ratio, beam section, area and pre-stress of cables and boundary conditions, on the failure load were investigated. Based on the comparison between elastic and elasto-plastic buckling loads, the effect of material non-linearity on the stability of the hybrid barrel vault is found significant. Furthermore, the stability of a hybrid barrel vault is sensitive to the anti-symmetrical distribution of loads. It is also shown that the structures are highly imperfection sensitive which can greatly reduce their failure loads. The results also show that the support conditions pose significant effect on the elasto-plastic buckling load of a perfect hybrid structure.

Collapse behavior of single-layer space barrel vaults under non-uniform support settlements

Abstract: Single-layer space barrel vaults are appropriate structures for covering extensive spaces with large spans for which non-uniform support settlement is considered as a great concern. This can affect the stability and collapse behavior of these structures. Accordingly, in this paper, the collapse behavior of the barrel vaults with different slope angles is investigated under various types of the non-uniform support settlement. Both material and geometrical nonlinearity are taken into account while studying the effects of the settlements on the collapse progression in barrel vaults. Finally, the optimum slope angles of the structures are determined so that it minimizes the destructive effects of the support settlement. Moreover, the allowable values of the non-uniform support settlements provided by several code provisions have been investigated in detail.

Tunnel vault steel arch frame mounting machine for existing railway tunnel disease repairing

Abstract: The utility model relates to a tunnel vault steel arch frame mounting machine for existing railway tunnel disease repairing, and belongs to the technical field of tunnel disease repairing construction equipment. The tunnel vault steel arch frame mounting machine for existing railway tunnel disease repairing comprises a mounting rack, a steel arch frame running mechanism, an electrical control part and a hydraulic control part, wherein the steel arch frame running mechanism is mounted on the mounting rack; the steel arch frame running mechanism consists of a steel arch frame position correcting device and a steel arch frame lifting and turnover device arranged on the side of the steel arch frame position correcting device; the steel arch frame lifting and turnover device consists of a lifting mechanism, a swing mechanism, a turnover mechanism and a fixing mechanism; and the steel arch frame position correcting device consists of a longitudinal moving mechanism, a transverse moving mechanism positioned above the longitudinal moving mechanism, an up-and-down moving mechanism fixed on the transverse moving mechanism, a locking mechanism and an up-and-down moving guide mechanism. By adoption of the tunnel vault steel arch frame mounting machine for existing railway tunnel disease repairing, a steel arch frame crossing carrier cable can be mechanically mounted, the labor intensity is greatly reduced, and the work efficiency and the safety are improved.

Settlement monitoring device for tunnel vault

Abstract: The utility model discloses a settlement monitoring device for a tunnel vault, which relates to a rock and soil mechanics monitoring technique. The device comprises a water level, a transfer rod plate, a vault hook, an invar rod, a modified invar rod, a bearing hanger rod and a bearing support rod, wherein the vault hook is arranged at a measuring point of a surrounding rock; the vault hook, the bearing hanger rod and the modified invar rod are orderly connected with one another up and down; the ground in a tunnel or the vault is provided with the transfer rod plate; the invar rod is arranged on the transfer rod plate; the water level on the ground in the tunnel or the vault is positioned between the invar rod and the modified invar rod. The settlement monitoring device disclosed by the utility model is simple in structure, quite convenient to mount, dismount and carry, economic, practical and easy to popularize, has high measurement precision, can satisfy the precision requirement on measured data in new Austrian tunneling construction of the tunnel, and is suitable for the condition that the height of the vault relative to the ground in the tunnel is continuously changed due to step-by-step construction of the tunnel.

Model experiment on effect of normal fault with 75°dip angle stick-slip dislocation on highway tunnel

Abstract: The paper conducts the research on the force-deformation mechanism under the effects of stick-slip dislocation of the normal fault with 75°obliquity by making use of 1∶50 model experimentAnd the strata pressure of the tunnel vault and bottom,axial strain and hoop strain are monitoredResult shows that with the normal fault rupture propagating in the overburden layer,the tunnel structure which is orthogonal to the normal fault will undergo relatively big shear displacementThe strata permanent deformation and the interaction between the strata and the tunnel structure causes the formation pressure changes significantly,of which the pressure on the vault in the hanging wall zone increases significantly,followed by the pressure on the vault in the foot wall zoneThe pressure on the tunnel bottom in the hanging wall zone decreases,while greatly increases in the foot wall zoneThat leads the tunnel being possibly separated from the wall rock so as to accommodate the shear displacement of the faultThe longitudinal bending moment in the hanging wall zone is positive and negative in the foot wall zoneBy judging the lining failure from the cement prototype under compression,the maximum allowed fault displacement of the prototype structure D = 125 m is determinedTheoretically,the value is overestimated

Tunnel vault detection device

Abstract: The utility model discloses a tunnel vault detection device which comprises geological radar, a flexible mechanism and a base seat. The geological radar is installed on the base seat through the flexible mechanism, and the flexible mechanism comprises a guide rail, a guide rail sliding block, a jackstay and a driving assembly. The guide rail is vertically arranged on the base seat, the jackstay is installed on the guide rail through the guide rail sliding block in a sliding mode, the jackstay is driven by the driving assembly to slide on the guide rail, and the geological radar is arranged at the top of the jackstay through a buffering mechanism which enables the geological radar to be elastically attached with the tunnel wall. The human labor handheld geological radar detection can be avoided by means of the added flexible mechanism, the detection security and stability can be improved, and the tunnel vault detection device can be applied to the tunnel detection.

Thin Concrete Barrel Vault

Abstract: The paper presents the structural design of a thin barrel vault constructed with Fusee Ceramique infill elements. The load transfer is analyzed and validated. For the structure composed of Fusee Ceramique elements, steel and concrete the stresses are calculated and compared to the stresses given in the codes used from 1950 to the present. The advantages and disadvantages of these low rise barrel vaults are showed. Further the possibilities of a light infill to reduce, for structures of concrete, the need of mortar, the self-weight and environmental load are discussed.