CN1737269A - Technique for spraying and stirring pile - Google Patents

Abstract

This invention relates to a spraying and stirring pile method, which belongs to civil engineering field, characterized in that the construction depth can reach to 35m, the cement consumption is small (10-20wt% of the earth), the diameter can be fixed (can be 50-100cm), and can penetrate standard penetration value N<=40 soil layer. The method designs, selects and manufactures the construction equipment as follows: the fixed mount beyond the length of the mount, gunite device, power unit with big twisting moment, the agitator (accompanying diagram2), cut-in screw blade; the method also designs the method of computing the processing parameter, characterized in that it uses the fixed number of leaves, the blade angle, the rotary rate and the water-cement ratio to make sure the cement paste pressure flow and the hoisting speed. The method will be mainly used in the following field: 1, industry and civil architecture foundation process; 2, railway and highway foundation process; 3, harbor, sluice, yard, oil can foundation process.

Description

Technique for spraying and stirring pile

Technical field:

Civil engineering

Background technology:

What at present method for processing foundation formed cement-soil has jet grounting and a deep mixing method.

Jet grounting: the big cement paste of working pressure (jet pressure is often greater than 20mp) the cutting soil body, injection flow is big, can have enormous impact to mix effect to the bigger cobble of diameter, gravelly soil.Handle the degree of depth at present and can reach more than the 30m, cement consumption is big.But owing to do not adopt stirring-head, the cement soil body diameter that forms in the soft or hard different soil does not wait.

The cement-soil paddling process: use fixedly stirring-head, cement paste water filling is under low pressure gone into the soil body and is stirred cement-soil fixed diameter after stirring.But, meet that underground rubble diameter is big slightly, plant roots and stems is difficult for passing.Construction depth has only 18m at present, forms the cement-soil quality and is difficult for guaranteeing (domestic a plurality of urban construction authorities' style of writing careful usefulness of indication or forbidding); At least need four to stir two sprays in the construction, speed is slower.

Summary of the invention:

The present invention is the novel construction method that is different from jet grounting and deep mixing method.

One, this worker method adopts: 1. high pulling torque power (4 ^T-MAbove moment of torsion); 2. bigger cement paste pressure (2～7mp); 3. organize stirring piece (7 groups～10 groups) more; 4. be provided with special spray and stir device, and 20 °～35 ° of 2 of cut-in type screw blades (accompanying drawing 2) incision lift angles are set in the end; 5. the high fixedly pile frame of 40m is set.

This worker method: 1. cement stirs, quality is good; 2. moment of torsion is big, and spray pressure is big, and has added the cut-in type screw blade, can pass and mould soil layer firmly; 3. spray pressure significantly improves than deep mixing method, can handle the degree of depth and reach 35m; 4. only need one on the other, speed is fast; 5. cement-soil fixed diameter; 6. cement consumption higher pressure injection slip casting method reduces significantly, and near the deep mixing method cement consumption, cost is low.

Two, this worker method process parameters design

1, predetermined major parameter calculates hoisting velocity

Pile body diameter d (m), number of blade ∑ Z, the wide h of blade (m), blade and shaft angle β (°), shaft speed of gyration (rev/min).Technological parameter N (cohesive soil is got 20, get 15) for sandy soil.Cut-in type flight lift angle θ (°).Device speed of gyration n is stirred in spray.

$V=\frac{h\cos \mathrm{\&beta;\&Sigma;Z}+2\&times;d\&times;\mathrm{tg\&theta;}}{N}n\&times;2$

2, by hoisting velocity checking computations whitewashing amount

$Q=\frac{\mathrm{VF}{\mathrm{\&gamma;a}}_w(1+a_c)}{{\mathrm{\&gamma;}}_d}$

γ in the formula _d, γ-be respectively cement paste and soil severe (kN/min);

Q-whitewashing amount (m ³/ min);

Sectional area (the m of F-agitation pile ²);

a _w--cement mixed ratio; (according to design commonly used fetch earth heavy by 10%～20%)

a _c--the cement paste water/binder ratio.(water/binder ratio can select 0.6～1.0 for use)

3, whether double calculation whitewashing amount and hoisting velocity are coordinated, and determine suitable mouth spray diameter according to whitewashing amount and hoisting velocity.Spray pressure is used 2～7mp always, and it is big to make the stake diameter, can select big pressure for use when soil layer is hard.The mouth spray diameter can be 0.5～1.0cm (it is big that the diameter I produces pressure).

4, calculate whitewashing amount and spray and stir the device hoisting velocity and can not universal time coordinated can adjust to give and decide parameter, until reaching calculation requirement.

Three, this worker method technological process: (with reference to accompanying drawing 1)

1, preparation slurries;

2, pile-forming machine perching;

3, sink to design elevation (subsidence velocity must not greater than the design hoisting velocity) by design subsidence velocity rotation;

4, press at the uniform velocity rotary lifting of design hoisting velocity, and simultaneously by design pressure and flow whitewashing.

Description of drawings:

Accompanying drawing 1 is the process equipment schematic block diagram.

Accompanying drawing 2 stirs the design structure of device for the spray of this worker method.The quantity of blade and determine that by design the cut-in type flight is 2 wherein with the shaft angle, its lift angle (θ) to the mark value of passing through N greatly N 〉=15 soil layers should get and be not more than 30 °; Should get 30 °～45 ° for the less soil layer N of the mark value of passing through＜15; The construction depth scope there be should considering by the maximum mark value of passing through soil layer in the soil layer of different soil.

Equipment material and section should carry out bending resistance, shearing resistance and reverse checking computations.

The mouth spray diameter should be determined according to design parameters.

The specific embodiment:

Select to adopt present existing production product; Slush pump, pile frame, stake machine running mechanism and high pulling torque power-equipment.Design and produce spray and stir device (seeing accompanying drawing 2).To different soil diameter designing and calculating parameters of construction technology, carry out test pile after, drop into formally construction.

Claims (1)

1. The technique for spraying and stirring pile claim.At present civil engineering groundwork handle adopt cement earth pile the slip casting method of injection and deep mixing method arranged.

   Spraying slip casting method is that construction length is big with water under high pressure mud (more than the normal 20mp) cutting soil, but the stake footpath is different in different soil, and cement consumption is big; Deep mixing method is fixing stirring vane, injects cement paste and forms cement earth pile, and its footpath can be fixed, and cement consumption is little, but construction length little (less than 18m), construction quality is difficult for guaranteeing.

   The feature of technique for spraying and stirring pile be with fixing spray stir device (Fig. 2) with slip casing by pressure (2～7mp), construction length can reach 35m, fixed diameter, cement consumption little (soil weighs 10%～20%) speed of application is fast, cost low (near deep-mixed pile).

   Dependent claims:

   1, the equipment of worker's method configuration and spray are stirred the device mode and are made: 3 ^T-MMore than twist power; 2～10mp spray pump; Fixing pile frame; The making (Fig. 2) that device is stirred in spray.

   2, the design of worker's method construction parameter: (two stir a spray), subsidence velocity, whitewashing hoisting velocity, pumping pressure, flow, the number of blade one on the other.

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