A kind of method for improving drift-sand area transmission line tower foundation extraction-resistant behavior
Technical field
The present invention relates to the foundation engineering technology of a kind of transmission line of electricity, be specifically related to a kind of for improving the transmission of electricity of drift-sand area
The method of overhead line structures foundation anti-pulling performance.
Background technology
Drift-sand is a kind of sandy soil with special nature, and its notable engineering characteristic is: granule is uniform, natural moisture content
Low (3%~about 10%), chance water have " settlement by soaking ".
Sand Movement is serious to industry harm such as highway, railway, transmission lines of electricity, current drift-sand area electric power line pole tower
Basis generally two kinds of modes of checking winds and fixing drifting sand of employing:
1) straw checkerboard barrier sand-protecting barrier fixes the sand: this kind of sand-fixation method generally takes the straw about length 50cm, imbeds 20-30cm in sand,
Expose outside Shamian Island 20-30cm, surround the grid of about 1m × 1m, be covered with basis, whole tower position extension with this kind of grid
2-3m.This mode of fixing the sand has a disadvantage in that owing to the things such as straw are easily degenerated, and generally at circuit running, needs
Safeguarding in time when patrolling and examining, maintenance period is usually 1-2;If safeguarding the most in time, owing to straw checkerboard barrier sand-protecting barrier fixes the sand mode
Single, cause engineering safety hidden danger;Basic stand column and sandy soil contact site, earth's surface easily because of the raw wind erosion of local wind's miscarriage, are led
Cause is appeared and is highly increased, and hides some dangers for engineering;
2) rubble paving presses solidly sand: this kind fixes the sand mode generally at the metalling that Shamian Island bedding 20cm is thick, and metalling is covered with whole
Individual tower position, basis extension 2-3m.This kind of mode can be prevented effectively from the wind erosion at basic stand column position.But due in desert,
Generally engineering materials obtain and manually transport to construction ground, and simple employing rubble paving presses solidly sand, and the rubble amount used is big, increases
Freight volume, improves the expense of fixing the sand.
The above-mentioned measure of checking winds and fixing drifting sand belongs to mechanical sand fixation mode, needs to utilize substantial amounts of raw material (straw or rubble),
This is for the transmission line tower foundation of some wire distribution, desert area raw material freight volume greatly, costly, and on
State the mode of checking winds and fixing drifting sand itself and there is limitation.
Accordingly, it is desirable to provide a kind of sand-fixation method overcomes disadvantages described above so that the overall adhesive aggregation characteristic of drift-sand is carried
Height, thus can reach technical measures and the method improving transmission line tower foundation extraction-resistant behavior.
Summary of the invention
For the deficiencies in the prior art, the present invention provides a kind of for improving drift-sand area transmission line tower foundation resistance to plucking
The method of performance, described method comprises the steps:
A, in ground excavate upper shed 9m*9m, deep 3m, 45 ° of extended corners, holes of end 3m*3m;
B, installation foundation: after the sandstone that paving 100mm is thick, lay basis;
C, drift-sand mix cement layer: in the drift-sand of drift-sand Yu the ratio of Portland cement weight ratio 100:3
The drift-sand of the batch mixing that mixes cement backfill 300~500mm mixes cement after layer and gives compacting;
After d, backfill foundation ditch to top layer, lay straw checkerboard barrier sand-protecting barrier or gravel paving pressure.
Preferably, described basis is transmission line tower foundation, comprising: arrange from top to bottom on same vertical direction
Digging foundation and rock build-in basis;Described digging foundation and rock build-in basis and which is provided with the reinforcing bar of foundation bolt
Cylinder mould build-in global formation.
Preferably, described digging foundation is made up of the basic chassis of cylindrical basis principal post and truncated cone-shaped;Described basis principal post
Surface layer is exposed on top, and bottom, chassis, basis couples the rock build-in basis of circular platform type.
Preferably, described foundation bolt from top to bottom through digging foundation and rock build-in basis and rebar cylinder mould inside.
Preferably, the length of described foundation bolt is more than the height sum of digging foundation with rock build-in basis, foundation bolt
Top is provided with packing ring, locking nut and concrete enclosing cap, and bottom is provided with crotch or is welded with anchor slab.
Preferably, described rebar cylinder mould is by the main muscle of vertical direction, horizontal direction outer ring stirrup and horizontal direction inner ring stirrup
Constitute.
Preferably, rebar cylinder mould is the outer ring stirrup of the main ribs by vertical direction and horizontal direction and inner ring stirrup is constituted
Cylinder;Main ribs is uniformly arranged between one outer ring stirrup and inner ring stirrup, and described muscle is welded to connect.
With immediate prior art ratio, the invention have the benefit that
The method for improving drift-sand area transmission line tower foundation extraction-resistant behavior that the present invention provides is by by common
The weight ratio of portland cement and drift-sand is set to 0.03:1, the breakout capacity anti-than common tower foundation improve 10~
15%, extend 8~12% service life, desert area can be reached again and check winds and fix drifting sand effect, and cement consumption is little,
Transmission line tower foundation freight volume simultaneously for spot distribution is the least, greatly reduces the cost checked winds and fixed drifting sand, and obtains
Significant economic benefit.
Accompanying drawing explanation
Fig. 1 is that the present invention improves electric power line pole tower base in the method for drift-sand area transmission line tower foundation extraction-resistant behavior
The front view of plinth;
Fig. 2 is A-A sectional view in Fig. 1;
Fig. 3 is B-B sectional view in Fig. 1;
Fig. 4 is the rebar cylinder mould structural representation of transmission line tower foundation in Fig. 1;
Description of reference numerals: 1 digging foundation, 1-1 basis principal post, chassis, 1-2 basis, 2 rock build-in bases, 3 ground
Foot bolt, 3-1 crotch, 4 rebar cylinder moulds, the main muscle of 4-1,4-2 outer ring stirrup, 4-3 inner ring stirrup, 5 coagulation graves
Close cap
Detailed description of the invention
Below the detailed description of the invention of the present invention is described in further detail.
In order to thoroughly understand the embodiment of the present invention, detailed structure will be proposed in following description.Obviously, the present invention is real
The execution executing example is not limited to the specific details that those skilled in the art is familiar with.Presently preferred embodiments of the present invention is detailed
It is described as follows, but in addition to these describe in detail, the present invention can also have other embodiments.
In the present invention, transmission line tower foundation selects to see shown in Fig. 1, Fig. 2 and Fig. 3, and the embodiment of the present invention provides
A kind of base structure of electric power line pole tower, this basis at least includes: digging foundation 1, rock build-in basis 2,
Foot bolt 3, rebar cylinder mould 4, concrete protective cap 5 etc.;Cover by argillic horizon on earth's surface, under cover for severely-weathered or in
Deng the base structure using digging foundation 1 and rock build-in basis 2 to combine under the geological conditions of weathered rock formation, it is achieved
The transmission line tower foundation such as this kind of area higher enforcement supertension of extraction-resistant behavior, extra-high voltage.
Specifically, as preferably, described digging foundation 1 and rock build-in basis 2 are by foundation bolt 3 and rebar cylinder mould
4 build-ins are solidifying to be integrated, and uses concrete one-time-concreting entirety build-in molding, and wherein, digging foundation 1 is positioned at earth's surface and glues
Soil layer, rock build-in basis 2 is positioned at severely-weathered or medium weathering rock stratum;Described digging foundation 1 by basis principal post 1-1 and
Basis chassis 1-2 is constituted, and wherein, basis principal post 1-1 is cylinder, and basis chassis 1-2 is circular platform type, described basis
The top of principal post 1-1 is exposed surface clay layer and is covered, and bottom couples the basic chassis 1-2 of circular platform type, basis chassis 1-2
Bottom couple circular platform type rock build-in basis 2.
Specifically, as preferably, the top of described basis principal post 1-1 is inserted with many foundation bolts 3, preferably four,
The specification of the value range base area foot bolt 3 that each foundation bolt 3 exposes basis principal post 1-1 is different and changes, its thing
Matter scope is 200-400mm;Foundation bolt 3 top is provided with packing ring and locking nut, uses concrete after having assembled
Pour one concrete enclosing cap 5 of molding, in order to protecting field foot bolt 3 and securing member;The length of described foundation bolt 3
More than the height sum of digging foundation 1 with rock build-in basis 2, foundation bolt 3 is from top to bottom through digging foundation 1
Internal with rock build-in basis 2 and rebar cylinder mould 4, foundation bolt 3 bottom is provided with crotch 3-1 or is welded with anchor slab,
To strengthen anchoring effect.
Referring also to shown in Fig. 4, specifically, described rebar cylinder mould 4 is by some main muscle 4-1, several outer ring stirrups
4-2 and several inner rings stirrup 4-3 is constituted;Described each main muscle 4-1 is longitudinally disposed along Y-axis, described outside each
Circle stirrup 4-2 and each inner ring stirrup 4-3 is along X-axis horizontally set;Some main muscle 4-1 are circumferentially uniformly distributed,
Several outer rings stirrup 4-2 and several inner rings stirrup 4-3 is along Y-axis longitudinal arrangement;Described the most equally distributed often
A piece main muscle 4-1 is uniformly arranged between each outer ring stirrup 4-2 and each inner ring stirrup 4-3, described outside each
Circle stirrup 4-2 and each inner ring stirrup 4-3 is the most arranged vertically along each main muscle 4-1, and interval is uniform, with each main muscle
4-1 contact point is pad, and is welded to each other together, thus constitutes the rebar cylinder mould 4 that cylinder is netted;Described bar-mat reinforcement
The height of cage 4 is more than the height of digging foundation 1, and rebar cylinder mould 4 is from top to bottom through in digging foundation 1 and extend to
Rock build-in basis 2 is internal, be mounted in digging foundation 1 and rock build-in basis 2 by concreting together with, institute
Stating the design height scope inserted in rock build-in basis 2 bottom rebar cylinder mould 4 is 600-1300mm, embedded depth of foundation 3m.
In order to improve drift-sand area transmission line tower foundation extraction-resistant behavior, mainly it is implemented with following steps:
(1) excavation of foundation pit: using and mechanically or manually excavate, top is excavated according to 45 degree of extended corners, top excavation size
9m*9m, bottom excavation size 3m*3m, cutting depth 3m, foundation ditch sandy soil excavated volume 117 side, drift-sand weight about 163.8
Ton;
(2) assembling type base is installed: require 100mm sand-gravel cushion according to design, lays assembling type base and successively will
Each connector is tightened;
(3) drift-sand mixes cement: according to 3% incorporation Portland cement of drift-sand weight, press in whipping process
Weight according to bagged cement adds sand, is at once backfilled in foundation ditch after stirring, and enters according to 300~500mm mono-layers
Row compacting, amounts to required incorporation Portland cement amount 4914kg.
(4) after foundation ditch is backfilled to top layer, laying straw checkerboard barrier sand-protecting barrier or gravel paving pressure, foundation construction is complete.
Transmission line tower foundation extraction-resistant behavior in above-described embodiment, pulls out in the assembling type base limit under normal conditions and holds
Load power is 500kN, and the assembling type base upper and low approximations in mixing cement mixing molding drift-sand ground is 600kN,
Its limit upper and low approximations improves about 20%.
According to correlational study achievement, the moisture content of drift-sand is typically about 3%, and Portland cement volume is 3%~6%
Time, the adhesive aggregation performance of drift-sand reaches optimal, and its Shear Strength Index C value improves more than 20%, and top layer is easily formed tool
Having the flexible bonding course of some strength, form protective layer on surface, sand dune, isolation air-flow directly acts on loose sand bed,
Ensure that the moisture of drift-sand is difficult to lose, adhesive aggregation performance is strengthened, reach to check winds and fix drifting sand and improve pole and tower foundation resistance to plucking and hold
Carry the effect that can manage it.
The present invention for improving the method for drift-sand area transmission line tower foundation extraction-resistant behavior by by common silicic acid
Salt cement is set to 0.03:1 with the weight ratio of drift-sand, and the resistance to plucking carrying significantly improving transmission line tower foundation can be manageed it,
Desert area can be reached again check winds and fix drifting sand effect, and cement consumption is little, simultaneously for the transmission line of electricity bar of spot distribution
Tower foundation freight volume is the least, greatly reduces the cost checked winds and fixed drifting sand, and achieves significant economic benefit
Finally should be noted that: above example only in order to illustrate that technical scheme is not intended to limit, although
Being described in detail the present invention with reference to above-described embodiment, those of ordinary skill in the field still can be to this
Bright detailed description of the invention is modified or equivalent, these without departing from spirit and scope of the invention any amendment or
Person's equivalent, all within the claims that application is awaited the reply.