CN204676585U - A kind of transmission line of electricity open caisson Screw Anchor composite foundation - Google Patents

Abstract

The utility model discloses a kind of transmission line of electricity open caisson Screw Anchor composite foundation.At present, conventional Screw Anchor and rigidity step base set are closed, but rigidity step base concrete large usage quantity, therefore this combination foundation cost is higher.Of the present utility modelly be characterised in that it is made up of upper and lower two parts, top is divided into open caisson foundation, bottom is divided into spiral anchor base, and the Screw Anchor anchor pole of described spiral anchor base is connected with the reinforcing bar binding of open caisson base plate and together concreting, forms a composite type base.The utility model make basis on pull out supporting capacity and greatly improve, viewed from loading angle, it is applicable to the basis that uplift force transmission line of electricity accounts for leading role, is highly suitable for the basis, outside of the large angle tower of transmission line of electricity, and has good economy.

Description

A kind of transmission line of electricity open caisson Screw Anchor composite foundation

Technical field

The utility model relates to the basis of a kind of open caisson and Screw Anchor compound, is applicable to the transmission line tower foundation that uplift force accounts for leading role, basis outside especially large angle tower.

Background technology

The main feature of open caisson foundation to bear larger vertical and horizontal loading.In addition, open caisson is basis, gear soil when being again construction and water-retaining cofferdam structure thing, its construction technology is easy, technology is reliably safe, without the need to special professional equipment, and can make compensated foundation, avoid excessive sedimentation, be commonly used in bridge pier and abutment, underground pump house and large equipment base, high level and super high rise building basic etc.In the area that underground water is more shallow, in open caisson construction process, when heavy pass through complete build base plate after, often can run into the problem of floating, therefore usually need its wall thickness designed comparatively large or increase load on top.

Spiral anchor base, as wood screw, rotatablely enters darker soil layer, turns the cylindrical soil body entering process disturbance, and after leaving standstill after a while, its intensity will have and recovers significantly, therefore can bear larger uplift load.Screw Anchor, according to the quantity of anchor dish, can be divided into single anchor dish spiral anchor base and many anchors dish spiral anchor base.But the downforce that spiral anchor base can bear is less, normal needs solves with coordinating of other pattern bases the problem of pressing down.At present, conventional Screw Anchor and rigidity step base set are closed, but rigidity step base concrete large usage quantity, therefore this combination foundation cost is higher.

Utility model content

Technical problem to be solved in the utility model is the defect overcoming the existence of above-mentioned prior art, and provide a kind of transmission line of electricity open caisson Screw Anchor composite foundation, it is applicable to the basis that uplift force in transmission line of electricity accounts for leading role, and has good economy.

For this reason, the utility model adopts following technical scheme: a kind of transmission line of electricity open caisson Screw Anchor composite foundation, it is characterized in that it is made up of upper and lower two parts, top is divided into open caisson foundation, bottom is divided into spiral anchor base, the Screw Anchor anchor pole of described spiral anchor base is connected with the reinforcing bar binding of open caisson base plate and together concreting, forms a composite type base.

After open caisson (inner backfill) and Screw Anchor combine, composite foundation pulls out supporting capacity and greatly improve, viewed from loading angle, it is highly suitable for the basis, outside of the large angle tower of transmission line of electricity.

In addition, for the engineering that underground water is very shallow, general open caisson sinking complete build base plate back cover after, it is just as an empty cup, the significant of anti-floating problem, and open caisson Screw Anchor composite foundation, before bottom sealing, be first about to Screw Anchor anchors into, build base plate again and Screw Anchor is become an entirety with open caisson bottom slab concreting, had the uplift effect of Screw Anchor thus, the On The Floating of open caisson has had very large alleviation, can reduce open caisson wall thickness, thus reduce the concrete work amount of open caisson, make open caisson Screw Anchor composite foundation have good economy.

Further, the inside backfill of described open caisson foundation, gives full play to soil in well and heavily carrys out resistance to plucking.

Further, described Screw Anchor is made up of described anchor pole and the anchor dish be arranged on anchor pole.The radical of Screw Anchor is not restricted, and determines according to practical basis active force, meets open caisson floating demand and base integral resistance to plucking.

The beneficial effect that the utility model has is as follows: make basis on pull out supporting capacity and greatly improve, viewed from loading angle, it is applicable to the basis that uplift force transmission line of electricity accounts for leading role, be highly suitable for the basis, outside of the large angle tower of transmission line of electricity, and there is good economy.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model.

Fig. 2 is the top view of Fig. 1.

Fig. 3-6 is work progress schematic diagram of the present utility model (Fig. 3 is open caisson manufacture, and Fig. 4 is well sinking, and Fig. 5 is that Screw Anchor is casted anchor, and Fig. 6 is bottom slab concreting).

In figure, 1-open caisson foundation, 2-spiral anchor base, 3-anchor pole, 4-open caisson base plate, 5-anchor dish.

Detailed description of the invention

Transmission line of electricity open caisson Screw Anchor composite foundation as shown in the figure, it is made up of upper and lower two parts, and top is divided into open caisson foundation 1, and bottom is divided into spiral anchor base 2.The Screw Anchor of described spiral anchor base 2 has three, and every root Screw Anchor is made up of the anchor dish 5 on anchor pole 3 and skyhook.The Screw Anchor anchor pole 3 of spiral anchor base 2 is connected with the reinforcing bar binding of open caisson base plate 4 and together concreting, forms a composite type base.The inside backfill of open caisson foundation 1.

One, basic constructional design

The method for designing of open caisson Screw Anchor composite foundation bearing capacity, upper and low approximations considers the mode superposed again with Screw Anchor separate computations by open caisson, presses down and considers all to be provided by open caisson foundation with lateral bearing capacity.Open caisson foundation pulls out, presses down, laterally stable computational methods carry out according to the relevant regulations in " aerial power transmission line basic engineering technical stipulation " DL/T 5219-2005.Screw Anchor is pulled out capacity calculation to carry out according to State Grid Corporation of China company standard Q/GDW584-2011 " overhead transmission line spiral anchor base designing technique specification " relevant regulations.

In addition its design in work progress is also comprised for Sinking Well Design and mainly comprise sinking checking computations, antifloating computation, and in the Intensity Design of construction stage and operational phase open caisson itself, specific design method is as follows:

(1) sink to checking:

Well sinking process comprises the checking computations of sinking feasibility and sinking stable calculation.

There is side friction between outer wall and the soil body time during well sinking, if do not take other measures, the effective gravity on basis must be made to be greater than survey frictional resistance, the feasibility that guarantee sinks, these checking computations adopt the method for sinking control coefficient to ensure:

k _st≥1.05

k _st＝(G _1k-F _fw,k)/F _fk

In formula

K _stfor subsidence factor;

G _1kfor open caisson deadweight standard value (comprising the additional standard value helping heavy amount), N;

F _{fw, k}for the uplift pressure standard value of water in sinking watching, N;

F _fkthe total frictional resistance standard value of the borehole wall, N;

The stable sinking coefficient of stability that adopts of the sinking of open caisson ensures, the genus that instantly avales is greater than 1.2, or when meeting soft layer in sinking watching, should carry out the sinking Stability Checking Calculation of open caisson according to actual conditions, now the sinking coefficient of stability should meet following formula requirement:

In formula

K _{st, s}for the sinking coefficient of stability, desirable 0.8-0.9;

F ' _{fw, k}buoyancy of water standard value under checking computations state, N;

F ' _fkthe total frictional resistance standard value of the borehole wall under checking computations state, N;

R _bfoundation soil ultimate bearing capacity sum under caisson cutting edge, partition wall and bottom girder, N.

(2) antifloating computation

The anti-floating problem of open caisson spiral anchor base, the same with common open caisson, mainly appear at bottom slab concreting when completing, the peak level that now antifloating computation occurs according to actual capabilities checks, and is not considering to meet following formula requirement under open caisson side friction condition:

k _fw≥1.0

$k_{\mathrm{fw}}=\frac{G_{1k}+\mathrm{\Σ}{T}_{\mathrm{ik}}}{F_{\mathrm{fw},k}^b}$

In formula

K _fwfor open caisson anti-floating coefficient;

for sole uplift pressure standard value, N;

T _ikfor the uplift resistance standard value of each Screw Anchor, N.

(3) Open Caisson strength calculates

Open Caisson strength calculates and comprises the calculating of sword pin; Borehole wall hoop calculates (before back cover); The vertical tension of the borehole wall of construction stage calculates; The borehole wall calculates (after bottom slab concreting); Base plate calculates.

Two. making step

(1) on-the-spot open caisson manufacture, is shown in Fig. 3;

(2) well sinking is to predetermined absolute altitude, sees Fig. 4;

(3) Screw Anchor is casted anchor, and sees Fig. 5;

(4) open caisson bottom slab concreting, is shown in Fig. 6;

(5) the inner backfill of open caisson;

(6) top cushion cap is built.

Claims (3)

1. a transmission line of electricity open caisson Screw Anchor composite foundation, it is characterized in that it is made up of upper and lower two parts, top is divided into open caisson foundation (1), bottom is divided into spiral anchor base (2), the Screw Anchor anchor pole (3) of described spiral anchor base (2) is connected with the reinforcing bar binding of open caisson base plate (4) and together concreting, forms a composite type base.

2. transmission line of electricity open caisson Screw Anchor composite foundation according to claim 1, is characterized in that, the inside backfill of described open caisson foundation (1).

3. transmission line of electricity open caisson Screw Anchor composite foundation according to claim 1 and 2, is characterized in that, described Screw Anchor is made up of the anchor dish (5) on described anchor pole (3) and skyhook.