CN104812962A - Plated pile for wet terrain or mud which can stand in stable position and needs no bedrock to rest on - Google Patents

Abstract

The present invention discloses a plated pile for wet terrain or mud which can stand in stable position and needs no bedrock to rest on. The pile (1) herein is made of steel pipe (1), wherein this pile (1) is equipped with a steel plate (2) of at least 1.20 m diameter and 16 mm thickness welded at a point spaced one-third of the entire length from the upper end of the pile (1) for retaining and ceasing of the downward movement of the pile (1) as well as stabilizing its upright position in mud or wet terrain. The distance of one-third of the entire length of the pile (1) from the upper end of the pile (1) is the same as the length of torque arm of the total hydrostatic force acting on the pile (1) with respect to the center of the mass of the pile (1). This equivalent balancing torque enables the pile (1) to sturdily stand upright in a stable position in mud or wet terrain.

Description

Can settling position be stood on and do not need rely on basement rock for the stake with plate in wetland or mud

Technical field

The present invention relates to stake, described stake improves according to hydrodynamics and principle of hydrodynamics, this improvement is realized in the position that the distance with its upper end is 1/3rd of the total length of stake by the Plate Welding of the radius by having regulation, make stake can to stablize upright position firmly upright in mud or wetland, and do not need to rely on basement rock, when the balance of stake is disturbed, because stake can be vibrated with damping mode, therefore it can bear relatively large load, and has resistance to earthquake.

Background technology

In the technology of existing stake, the position of basement rock in wetland or mud is darker, then stake needs the length more grown to arrive basement rock.After arrival basement rock, then stake is knocked, embedding in basement rock closely.But although need cost a lot of money energy, high operating cost, a large amount of operation energy and a large amount of operating time, in this work, the risk that stake is collapsed is still very high.

Stake of the present invention is with based on hydrodynamics and fluid dynamic principle design, make when it is applied in mud or wetland, it does not need to rely on basement rock, and only needs a small amount of steel pipe (parts of stake) that stake just can be made in mud firmly to stand on very stable position.Stake can stand on settling position, this be due to its keep by relatively large restoring force, described restoring force is the effect due to surface of steel plate, described steel plate be welded on be positioned at stake center of gravity above the position of spaced apart default distance.Restoring force is equal relative to the torque of the center of gravity of stake with the total hydrostatic be applied to by mud in stake relative to the torque of the center of gravity of stake.Distance from the steel plate of welding to the upper end of stake is 1/3rd (12m) of the total length (H) of stake.This distance with the total hydrostatic center acted in stake to stake lower end between distance equal.

The other advantage of stake of the present invention is that it has stronger support loading ability, and has resistance to earthquake, and when this is owing to there is earthquake or displacement when working region, this stake can vibrate the several seconds (damped harmonic oscillation swings) before stopping.

The power acted in stake is gravity (F respectively _w), newton's buoyancy (F _b), frictional force (F _v) and resistance (F _p), described frictional force is the viscosity due to medium, and described resistance is provided by the surface of circular steel plate.

Summary of the invention

Target of the present invention is the quantity being minimized in the stake used in mud or wetland, maximizes pile by the ability of load, promotes the stability of stake, but in mud stake can being installed in do not have basement rock or have the position residing for basement rock basement rock darker or wetland.

Accompanying drawing explanation

Fig. 1 is the longitdinal cross-section diagram according to stake of the present invention.

Fig. 2 is the longitdinal cross-section diagram of the part according to stake of the present invention, and its light plate is soldered to this part of stake and the support had for strengthening.

Fig. 3 is the plan view of steel plate, and after described steel plate adopts support to be reinforced, described steel plate is welded in stake.

Fig. 4 is the stake with steel plate, and described steel plate is welded in stake, and now stake drops in mud or wetland.

Detailed description of the invention

Be made up of steel pipe according to stake of the present invention (1), and by welding and the position of upper end interval 1/3H or 12m of stake radius (R is equipped with _p) be the steel plate (2) of 0.60m.The distance 1/3H (12m) of the upper end of distance stake is equal to the distance at the total hydrostatic center acted in stake with the lower end from stake.Equal torque arm length makes stake after being equipped with steel plate, upright (can not tilt) that can be firm in the highly stable position in mud or wetland.The thickness of steel plate is 1.6cm (16mm).In order to steel plate is closely fixed in stake, stake employing support (3) is reinforced, this support in having the form with four rectangular steel plates of bent upper end edges of 90 degree of being spaced apart from each other on steel plate, and all extends 47.5cm (as shown in Figure 2) in longitudinal direction and radial direction respectively.

The advantage of stake of the present invention is disclosed by the hydrodynamics and principle of hydrodynamics being used as Fig. 4 of reference.

Fig. 4 shows according to the stake being equipped with steel plate of the present invention, this steel plate and the position of upper end interval 12m (h) of stake be welded in stake.

The length of stake is H (36m).First pile by lower in mud, until the degree of depth reaches (H-h) rice, i.e. the position of Plate Welding.Then the stake degree of depth that is knocked distance steel plate y rice or the degree of depth moved to joint efforts apart from steel plate y rice that makes stake energy Following effect in stake unfetteredly.The density of mud is ρ _lkg/m ³, and there is viscosity, mu handkerchief. second (pool).The quality that stake and load add up to is m kilogram, and the radius of stake is R rice, and the radius of steel plate is R _price, and acceleration of gravity is g meter per second ².

The power acted in stake is gravity (F respectively _w), newton's buoyancy (F _b), frictional force (F _v) and confining force (F _p), described frictional force is the viscosity due to medium, and described confining force is provided () by plate.

F _W＝mg，

F _B＝πR ²(H-h+y)ρ _Lg，

$F_v=\mathrm{\μ}\frac{d}{\mathrm{dt}}\left[2\mathrm{\πR}(H-h+y)\right]=2\mathrm{\πR\μ}\frac{\mathrm{dy}}{\mathrm{dt}},$

F _P＝π(R _P ²-R ²)ρ _Lgy。

Stake is made to move down=the F that makes a concerted effort _w-F _b-F _v-F _p,

$m\frac{d^{2}y}{{\mathrm{dt}}^2}=\mathrm{mg}-\mathrm{\π}{R}^2(H-h+y){\mathrm{\ρ}}_{L}g-2\mathrm{\πR\μ}\frac{\mathrm{dy}}{\mathrm{dt}}-\mathrm{\π}({R_P}^2-R^2){\mathrm{\ρ}}_L\mathrm{gy},$

$m\frac{d^{2}y}{{\mathrm{dt}}^2}+2\mathrm{\πR\μ}\frac{\mathrm{dy}}{\mathrm{dt}}+\mathrm{\π}{\mathrm{\ρ}}_{L}g({R_P}^2-{2R}^2)y=\mathrm{mg}-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_{L}g,$

(2πRμ) ²-4mπρ _Lg(R _P ²-2R ²)＜0。

Solve this differential equation can obtain

$y\left(t\right)=e^{\mathrm{Pt}}(A\cos \mathrm{Qt}+B\sin \mathrm{Qt})+\frac{m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)},$

$V\left(t\right)=\frac{\mathrm{dy}}{\mathrm{dt}}=e^{\mathrm{Pt}}[(\mathrm{BP}-\mathrm{AQ})\sin \mathrm{Qt}+(\mathrm{AP}+\mathrm{BQ})\cos \mathrm{Qt}].$

Wherein

$P=-\frac{\mathrm{\πR\μ}}{m},$

$A=\frac{[m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L]}{\mathrm{\π}{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)},$

$B=-\frac{\mathrm{R\μ}[m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L]}{{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)\sqrt{\mathrm{\π}{\mathrm{\ρ}}_L\mathrm{mg}({R_P}^2-{2R}^2)+{\mathrm{\π}}^2{R}^2{\mathrm{\μ}}^2}}.$

As t=0,

Y (t)=0 and v (t)=0.

When t=∞ (infinite),

$y\left(t\right)=y_{\∞}=\frac{m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)},$ And v (t)=0.

Y (t) and v (t) show stake viscosity, mu handkerchief due to mud in mud or wetland. second (pool) and swing mode oscillation with damped harmonic oscillation.Through after a while, the speed of stake reduces, and declines and finally rest on the degree of depth

$\begin{array}{c}d=(H-h)+y_m,\\ =(H-h)+\frac{m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)}.\end{array}$

Still the length standing upright on more than mud surface is H-y _m=12-y _mor

$12-\frac{m-{\mathrm{\πR}}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)}.$

Frequency (f) and the cycle (T) of stake vibration are respectively

$f=\frac{1}{2\mathrm{\π}}\·\frac{1}{m}\sqrt{\mathrm{\π}{\mathrm{\ρ}}_L\mathrm{mg}({R_P}^2-2R^2)+{\mathrm{\π}}^2{R}^2{\mathrm{\μ}}^2},$

$T=\frac{2\mathrm{\πm}}{\sqrt{\mathrm{\π}{\mathrm{\ρ}}_L\mathrm{mg}({R_P}^2-{2R}^2)+{\mathrm{\π}}^2{R}^2{\mathrm{\μ}}^2}}.$

The fact that this theory and this area run into is consistent, that is, stake of the present invention does not need to rely on basement rock in mud or wetland, and 2) the stake load that can carry is relative very large.

If the maximum load that stake can be born is M _mkg, and the quality of stake is M _tkg, therefore m=(M _t+ M _m), M _mcan easily calculate from following equation:

$\frac{(M_T+M_M)-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L({R_P}^2-{2R}^2)}=12,$

M _M＝12(R _P ²-2R ²)+πR ²(H-h)ρ _L-M _T。

Exemplarily (do not limit the scope of the invention), the density of the stake of being made up of steel pipe is 7.86 × 103kg/m ³, length is 36m, and external diameter is 0.125m, and thickness is 0.016 meter of (mass M of stake _tfor 3326.523kg), and radius R is equipped with _pthe steel plate of=0.60m, it is 2.5 × 103kg/m that described stake is applied to density ³(ρ _l) mud in, the maximum load M that stake can be born _mit is 30.58 tons.

If same stake is not equipped with above-mentioned steel plate, the differential equation that stake is moved in mud can be provided by following equation:

$m\frac{d^{2}y}{{\mathrm{dt}}^2}+2\mathrm{\πR\μ}\frac{\mathrm{dy}}{\mathrm{dt}}-\mathrm{\π}{\mathrm{\ρ}}_{L}g{R}^{2}y=\mathrm{mg}-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_{L}g,$

(2πRμ) ²+4m(πρ _LgR ²)＞0，

$y\left(t\right)=C_1{e}^{n_{1}t}+C_2{e}^{n_{2}t}-\frac{\{m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L\}}{\mathrm{\π}{\mathrm{\ρ}}_L{R}^2},$

$v\left(t\right)=n_1{C}_1{e}^{n_{1}t}+n_2{C}_2{e}^{n_{2}t},$

$n_1=-\frac{\mathrm{\πR\μ}}{m}+\frac{1}{m}\sqrt{{\left(\mathrm{\πR\μ}\right)}^2+\mathrm{\πm}{\mathrm{\ρ}}_{L}g{R}^2},$

$C_1=0.5[1+\frac{\mathrm{\πR\μ}}{\sqrt{{\left(\mathrm{\πR\μ}\right)}^2+\mathrm{\π}{\mathrm{m\ρ}}_L{R}^2}}]\left[\frac{m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L{R}^2}\right],$

$n_2=-\frac{\mathrm{\πR\μ}}{m}-\frac{\sqrt{{\left(\mathrm{\πR\μ}\right)}^2+\mathrm{\πm}{\mathrm{\ρ}}_{L}g{R}^2}}{m},$

$C_2=0.5[1-\frac{\mathrm{\πR\μ}}{\sqrt{{\left(\mathrm{\πR\μ}\right)}^2+\mathrm{\πm}{\mathrm{\ρ}}_L{R}^2}}]\left[\frac{m-\mathrm{\π}{R}^2(H-h){\mathrm{\ρ}}_L}{\mathrm{\π}{\mathrm{\ρ}}_L{R}^2}\right].$

If Y (t) and V (t) show t=0, then y=0 and v=0.And if t=∞ (infinite), then y is infinite and v is infinite.This just means and to be lowered in stake or to be embedded into after in mud or wetland, is not equipped with the stake of steel plate can experience downward accelerated motion, until reach the degree of depth (sinking) that can't see end.If stake arrives the basement rock that may be present in mud, this downward athletic meeting stops.If basement rock is present in following depths, surface, just need a large amount of stakes to arrive basement rock.This is one of shortcoming belonging to prior art.The present invention attempts providing this shortcoming and inefficient solution.

Claims (2)

1. a stake of being made up of steel pipe, described stake is applied in mud or wetland, described stake does not need to rely on basement rock, relatively large load can be born, can not collapse or tilt and be in place, and due to when the balance of described stake is disturbed, described stake can have resistance with damping mode vibration to earthquake, it is characterized in that, diameter at least 1.2m and the steel plate that thickness is at least 16mm is welded on and the total length of stake described in the upper end interval of described stake 1/3rd position, to keep and to stop moving downward of described stake, make described stake be stabilized in stand up position in mud or wetland simultaneously.

2. the application according to the stake described in claim 1 with steel plate.