Dynamic response of buried infusion pipeline under axial seismic excitation (1)

The main cause of damage to buried pipelines is axial deformation. The deformation forms include pull-off, pull-off, axial buckling and crushing. The degree of damage of the buried pipeline parallel to the direction of propagation of the seismic wave is much more serious than that of the buried pipeline perpendicular to the direction of propagation of the seismic wave, that is, the ground that propagates along the axial direction of the buried pipeline.

The main cause of damage to buried pipelines is axial deformation. The deformation forms include pull-off, pull-off, axial buckling and crushing. The degree of damage of the buried pipeline parallel to the direction of propagation of the seismic wave is much more serious than that of the buried pipeline perpendicular to the direction of propagation of the seismic wave, that is, the seismic wave propagating along the axial direction of the buried pipeline is more likely to cause damage to the pipeline. Based on the interaction between the pipeline and the soil and the interaction between the pipeline and the liquid, the dynamic response of the buried pipeline under the action of the compression wave transmitted in the axial direction is studied.

1 Vibration model and assumptions For the buried long straight pipeline, a length L can be taken as the research object. When L is long enough, the boundary condition has little effect on the response of the middle part of the L section. When studying axial vibration, the simplified model of the buried pipeline is shown in kx, which is the stiffness and damping of the soil around the unit length pipeline.

The ground motion is translational and has no rotational component; the pipeline is a continuous pipeline, that is, the pipe joint is the same as the other parts of the pipeline; the fluid is filled with the pipeline, is not compressible, and the fluid flow rate is constant; the medium in the pipeline is uniform in nature.

2 Soil stiffness and viscous damping 28; Reviewer: Sun Jiangang Fund Project: Heilongjiang Provincial Natural Science Fund Project (A9623) 3 axial vibration motion differential equation and finite element discretization of the wall micro-dimension force analysis results.

The equation of motion is that the force analysis of the pipe micro-element is displaced along the X-axis, and u'=u+Ugu' is the absolute displacement of the pipe.

Discrete the shape function, and take 4 cases to consider the horizontal continuous pipe length of length L, take L=200m. A sinusoidal acceleration pulse wave is transmitted from one end to the other along the axial direction of the pipeline at the propagation velocity of c. The acceleration expression of the site is other time; the corresponding field displacement expression is other time; ~ is the maximum axial relative displacement (Umax) and the maximum axial stress Umax at the flow velocity and L/2 at different soil shear moduli. The relationship curve.

It can be seen from ~ that, when V<50m/s, as the soil shear modulus increases, the axial relative displacement decreases, and the axial stress decreases is not obvious; as the outer diameter of the pipe increases, the axial relative displacement increases. The axial stress reduction is not obvious; as the flow rate increases, the axial relative displacement increases and the axial stress does not change.

358 security mesh fence made from a type of strong welded mesh panel with small mesh opening. It is extremely difficult to penetrate and difficult to attack using conventional hand tools. Has the features of anti-climbing and anti-cutting. 
The fence name 358 comes from its panel mesh opening 3" × 0.5" × 8 gauge - approximate to 76.2mm × 12.7mm × 4mm mesh opening.
Main advantage as follows:
1.Anti-climbing: more small openings, no toe or finger holds.
2.Anti-cut: robust wire and welded joints make cutting very difficult by bolt cutters and wire cutters.
3.High strength welded at each intersection.
4.Durable: covering Galfan and polymer powder coating ensure a long service life.
5.Mesh fencing specially configured to provide maximum visibility, especially used for emergency and electronic detection systems.

Products

Reference

Height

(mm)

Width

(mm)

 V(mm)  H Wire Thickness
Anti climb-900 900 2400 75 12.5/25 4
Anti climb-1200 1200 2400 75 12.5/25 4
Anti climb-1500 1500 2400 75 12.5/25 4
Anti climb-1800 1800 2400 75 12.5/25 4
Anti climb-2100 2100 2400 75 12.5/25 4
Anti climb-2400 2400 2400 75 12.5/25 4
Anti climb-2700 2700 2400 75 12.5/25 4
Anti climb-3000 3000 2400 75 12.5/25 4
Anti climb-3300 3300 2400 75 12.5/25 4
Anti climb-3600 3600 2400 75 12.5/25 4
Post Specification 50x50 50x75 65x65 60x60 4
 

358 Fence

358 Fence,358 Mesh,Anti Climb Fence,358 Anti Climb Fence

Anping Bochuan Wire Mesh Co., Ltd. , https://www.wiremeshbocn.com