CN102677692A - Method for fabricating large full-capacity tank pile foundation of liquefied natural gas - Google Patents

Abstract

The invention relates to a method for fabricating a large full-capacity tank pile foundation of liquefied natural gas, which comprises the steps of: 1) determining total load supported by the pile foundation to be fabricated, 2) selecting a pile shape, 3) checking the thickness of a concrete protective layer of the pile before irrigating, 4) primarily obtaining the quantity of the pile, 5) determining the pile distribution principle, 6) determining the safety condition met by actual quantity of the pile, 7) calculating and checking the vertical bearing capacity of the single pile under various work conditions, 8) calculating and checking the horizontal bearing capacity of the single pile under various work conditions, 9) carrying out tension calculation on the pile of bearing pulling resistance, 10) respectively calculating the settling amount of the storage tank foundations of a friction pile and a socketed pile according to actual engineering geologic type and comparing with the settling amount with the setting amount stated by practical engineering requirements, 11) carrying out reinforcement computation on the friction pile and the socketed pile according to an internal force formula of the pile body so as to obtain the rebar reinforcement area As of the single pile and further obtain the quantity of the rebars required by the single pile, and 12) distributing the piles according to the quantity of the pile and the reinforcement area so as to finish the fabrication of the foundation pile. The method for fabricating the large full-capacity tank pile foundation of liquefied natural gas disclosed by the invention can be widely applied to fabrication of the large full-capacity tank pile foundation of liquefied natural gas.

Description

A kind of large-scale liquefied natural gas holds the preparation method of storage tank pile foundation entirely

Technical field

The present invention relates to a kind of preparation method of pile foundation, particularly hold the preparation method of storage tank pile foundation entirely about a kind of large-scale liquefied natural gas.

Background technology

Liquefied natural gas (LNG) is a natural gas when under normal pressure, being cooled to-162 ℃, changes liquid state into by gaseous state, and volume is about with 1/600 of amount natural gas volume, and density is about 450kg/m ³Colourless, tasteless, the nontoxic and non-corrosiveness of liquefied natural gas can directly evaporate after the leakage.

It is the important component part that storage tank is built that the storage tank pile foundation is made; Its making optimization is the emphasis and the difficult point of storage tank construction work; The construction of land liquefied natural gas receiving station has all been launched in now a lot of cities; But the research of key issues such as the selection ground, the stake number that hold the storage tank pile foundation entirely for large-scale liquefied natural gas in the prior art are confirmed, Safety Design optimization still also is not very clear; There do not have complete pile foundation to make to be theoretical, and especially to the preparation method of socketed pile, there is technological gap in domestic, external at present theoretical research; Therefore press for a kind of preparation method that is applicable to the novel pile foundation of large-scale LNG tank of exploitation, this all has very important meaning for the safety of structure that guarantees LNG tank, reduction construction costs, saving duration.

Summary of the invention

To the problems referred to above, it is low and can guarantee effectively that the large-scale liquefied natural gas of tank structure safety holds the preparation method of storage tank pile foundation entirely to the purpose of this invention is to provide a kind of construction costs.

For realizing above-mentioned purpose; The present invention takes following technical scheme: 1, a kind of large-scale liquefied natural gas holds the preparation method of storage tank pile foundation entirely; May further comprise the steps: 1) hold the weight and the external condition of storage tank entirely, confirm to wait to make the required full payload of bearing of pile foundation according to the large-scale liquefied natural gas of the required carrying of reality; 2) select a stake type, and according to the stake footpath of selected stake with go into the load that the rock degree of depth confirms that single pile can bear; 3) before the perfusion thickness of concrete cover of stake is checked, to guarantee that reinforcing bar is not corroded in the stake; 4) full payload of utilizing pile foundation to bear tentatively obtains a number divided by the load that single pile can bear; 5) confirm the principle that lays out pile; 6) confirm the several safety conditions that satisfy of actual stake<img file="BDA00001678276600011.GIF" he="120" img-content="drawing" img-format="GIF" inline="yes" orientation="portrait" wi="234" />In the formula, n is the stake number, and μ is a safety factor, V<sub >0</sub>Be total vertical force, R<sub >Ad</sub>For liquefied natural gas holds storage tank vertical bearing capacity of single pile characteristic value entirely; 7) under each operating mode, calculate and check the vertical bearing capacity of single pile, as the vertical bearing capacity of single pile that calculates during: V less than the bearing capacity of single pile characteristic value<sub >D1</sub>, V<sub >D2</sub><r<sub >Ad</sub>, think that this vertical carrying structurally is safe, then gets into step 8); If vertical bearing capacity of single pile does not satisfy the checking computations requirement, then return step 6) and increase safety factor, confirm the stake number again, satisfy the checking computations requirement up to vertical bearing capacity of single pile, wherein, V<sub >D1</sub>And V<sub >D2</sub>Be single-pile vertical orientation power, R<sub >Ad</sub>For liquefied natural gas holds storage tank vertical bearing capacity of single pile characteristic value entirely; 8) horizontal bearing capacity of calculating and check single pile under each operating mode is worked as γ<sub >0</sub>H<sub >i</sub>＜η<sub >h</sub>R<sub >Ha</sub>, think that horizontal bearing capacity of single pile satisfies the checking computations requirement, get into step 9), if horizontal bearing capacity of single pile does not satisfy the checking computations requirement, then return step 6) and increase safety factor, confirm the stake number again, satisfy the checking computations requirement up to horizontal bearing capacity of single pile, wherein, γ<sub >0</sub>H<sub >i</sub>Be to calculate the suffered horizontal force of single pile, η<sub >h</sub>R<sub >Ha</sub>It is the horizontal bearing capacity that stake itself is had; 9) the resistance to plucking checking computations are carried out in the stake of bearing uplift resistance,, then returned step 6), increase safety factor, readjust a number,, then get into step 10) up to satisfying the checking computations requirement if the resistance to plucking checking computations do not meet the demands; 10) according to actual engineering geology type; Calculate the tank foundation settling amount of friction pile and socketed pile respectively, the sedimentation value of stipulating with actual engine request compares, if greater than the sedimentation value of stipulating; Then return step 6) and increase safety factor; Again confirm a stake number, satisfy the checking computations requirement, the entering step 11) up to the tank foundation settling amount of friction pile and socketed pile; 11) according to pile body internal force formula friction pile and socketed pile are carried out Reinforcement Calculation respectively, obtain the reinforcing bar area of reinforcement A of single pile<sub >s</sub>, and further obtain the required number of steel bars of single pile, and wherein, A<sub >s</sub>Be through<img file="BDA00001678276600021.GIF" he="84" img-content="drawing" img-format="GIF" inline="yes" orientation="portrait" wi="700" />Find the solution and obtain, in the formula, M is the pile body moment of flexure, f<sub >c</sub>Be concrete crushing strength design load, f<sub >y</sub>Be longitudinal reinforcement tensile strength design load, r is the stake section radius, r<sub >s</sub>Be the radius of longitudinal reinforcement center of gravity place circumference, α is corresponding to the central angle of pressure zone concrete section area and the ratio of 2 π, α<sub >1</sub>Be coefficient, α<sub >t</sub>Be the ratio of longitudinal tensile area of reinforcement with whole longitudinal reinforcement section area; 12) lay out pile according to the stake number and the area of reinforcement, accomplish the making of foundation pile.

The said step 5) principle of confirming to lay out pile comprises lay out pile shape and pilespacing, and wherein, the shape that lays out pile is that storage tank outermost two circles or three circle anchor ear shapes are arranged, the cross layout of inner stake, and a clump of piles is symmetric arrangement around the center; Pilespacing

At storage tank cushion cap radius is R _cThe storage tank cushion cap in according to S _aLay out pile, n is the stake number, storage tank cushion cap area $A_c=\frac{\mathrm{\&pi;}{\mathrm{<figure-callout\; id="2"\; label="R\; c"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">R</figure-callout>}}_c^{}}{4}.$

Single-pile vertical orientation power is in the said step 7): V _D1, V _D2=V ₀/ n ± { M ₀+ (1+ β * h)/(2 * β) * H ₀}/Z _G, in the formula, V ₀Be total vertical force, n is the stake number, M ₀Be moment of flexure, H ₀Be horizontal force, β is the stake characteristic value, and h is a floor board framing outage degree, Z _GBe clump of piles section modulus, wherein,

D is the diameter of stake, and E is the vertical modulus of elasticity of stake, and I is the stake second moment of area, k _hBe foundation soil horizontal reacting force coefficient;

R _iBe the peel off distance of pile center of i pile, R _MaxIt is the peel off distance of pile center of outmost turns stake.

Said moment M ₀Comprise two kinds of situation: based on total moment M of OBE situation _{0, OBE}With total moment of flexure V based on the SSE situation _{0, SSE}Wherein, M _{0, OBE}=M _{1, OBE}+ M _{2, OBE}+ M _{3, OBE}+ M _{In, OBE}, in the formula, M _{1, OBE}Be base plate moment of flexure, M _{2, OBE}Be exterior wall moment of flexure, M _{3, OBE}Be concrete bending square, M _{3, OBE}Be concrete bending square, M _{In, OBE}Be interior jar of moment of flexure; V _{0, SSE}=V _{1, SSE}+ V _{2, SSE}+ V _{3, SSE}+ V _{In, SSE}, V _{1, SSE}Be base plate vertical force, V _{2, SSE}Be exterior wall vertical force, V _{3, SSE}Be concrete top vertical force, V _{In, SSE}Be interior jar of vertical force.

The tank foundation settling amount of socketed pile is in the said step 10):

$S=(\mathrm{\&sigma;}-{\mathrm{<figure-callout\; id="4"\; label="q\; st"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{st}}\frac{4\mathrm{\&zeta;}{H}_t}{d})(\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}+\frac{H_t}{E_c})$

$\mathrm{\&sigma;}=V_{d1}/(\frac{\mathrm{\&pi;}}{4}\&CenterDot;d^2)$

In the formula, S is stake top sedimentation; σ is a stake top stress; q _StBe stake side soil layer standard side friction; ζ is a soil layer side friction coefficient; E _cBe the pile concrete modulus of elasticity; H _tBe the last overburden layer degree of depth; D is the diameter of stake; K ₂Be embedding rock section stiffness factor, wherein, ζ and last overburden layer depth relationship are: ζ=1.3445-0.01975Ht, K ₂With embedding rock depth relationship be: K ₂=(0.2114H _w/ d-0.09711)/d.

The area of reinforcement A of friction pile in the said step 11) _sIn the calculating,

Wherein, K=ab ₁Mz, a are each soil thickness; b ₁It is the molded breadth of stake; M is the factor of proportionality of foundation soil; Z is the distance of each soil layer mid point apart from ground, and l is that stake is long, and H is a top horizontal loading; In the Reinforcement Calculation of socketed pile, M=0.0655f _RkD (0.7h) ², in the formula, f _RkBe the saturated single shaft compressive strength standard of rock value, h is that the rock degree of depth is gone in stake, and d is the stake footpath.

The present invention is owing to take above technical scheme; It has the following advantages: 1, preparation method of the present invention comprises that a type is selected, the stake number is confirmed, pile vertical carrying capacity calculates and check, the checking computations of stake horizontal bearing capacity, the checking computations of stake resistance to plucking, pile foundation sedimentation checking computations and stake Reinforcement Calculation; Contain the full content that large-scale liquefied natural gas holds the design of storage tank pile foundation entirely, therefore can effectively guarantee the tank structure safety.2, the present invention is based on earthquake response spectrum and manage method; Used the Seismic Design theory of SSE (safe stoppage in transit earthquake) and OBE (earthquake of operation benchmark); And, respectively single-pile vertical orientation power, horizontal force and moment of flexure are calculated to SSE and two kinds of situation of OBE respectively by pile capacity in calculating and check; And the practical engineering experience method for designing incorporated in the making of the present invention, not only make result of calculation more accurately but also more meet the needs of actual engineering.3, the present invention carries out sedimentation checking computations and Reinforcement Calculation to socketed pile respectively, solved present socketed pile and made blank problem, for from now under different geological conditionss the large-scale liquefied natural gas of construction hold the storage tank stake full foundation be provided.The present invention can be widely used in the making that large-scale liquefied natural gas holds the storage tank pile foundation entirely.

Description of drawings

Fig. 1 is a preparation method schematic flow sheet of the present invention;

Fig. 2 is a single pile inner forces calculation embodiment sketch map of the present invention; Being connected between its king-pile and the lower face is set to fixedly connected; Soil layer is reduced to the nonlinear spring unit to the horizontal restraint of stake with vertically retraining, applies horizontal loading and vertical load at pile crown simultaneously;

Fig. 3 is a single pile calculation of Bending Moment process sketch map of the present invention, and the computation model of Fig. 2 has been carried out parameterized definition, wherein, and M _iBe pile crown moment of flexure, H _iBe pile crown horizontal loading, V _iBe pile crown vertical load, K _iBe the soil layer spring rate;

Fig. 4 is a socketed pile subsidence curve back segment match sketch map of the present invention, and abscissa is represented pile top load, and ordinate is represented a top sedimentation, and solid line is a stake top subsidence curve, and dotted line is a stake top sedimentation fitting a straight line;

Fig. 5 is soil layer side friction coefficient of the present invention and last overburden layer depth relationship data fitting sketch map, and wherein, abscissa is last overburden layer depth H _t, ordinate is soil layer side friction coefficient ζ, and stain is the actual tests data point, and straight line is that all experimental data matches form;

Fig. 6 is embedding rock section stiffness factor of the present invention and embedding rock depth relationship sketch map, and abscissa is the ratio H of the embedding rock degree of depth and pile body diameter _w/ d, ordinate are the product K of embedding rock section stiffness factor and pile body diameter ₂D, stain are the actual tests data point, and straight line is that all test data fittings form;

Fig. 7 is a stake sectional reinforcement sketch map of the present invention, and dash area is the pressure zone scope in a cross section, and empty circles is a longitudinal reinforcement, and r is the stake section radius, r _sBe the radius of place, longitudinal reinforcement center circumference, α is that π α is corresponding to 1/2 of the central angle (rad) of pressure zone scope concrete section area, α corresponding to the central angle (rad) of pressure zone scope concrete section area and the ratio of 2 π _tBe the ratio of longitudinal tensile district scope area of reinforcement with whole longitudinal reinforcement section area, π α _tFor the π of longitudinal tensile district scope area of reinforcement and whole ratio of longitudinal reinforcement section area doubly.

The specific embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is carried out detailed description.

As shown in Figure 1, large-scale liquefied natural gas of the present invention holds the preparation method of storage tank pile foundation entirely, may further comprise the steps:

1, weight and the external condition of holding storage tank according to the large-scale liquefied natural gas of the required carrying of reality are entirely confirmed the full payload of the required carrying of pile foundation to be made, and wherein external condition comprises factors such as geological process and wind-force.

2, select a stake type, and based on the stake footpath of selected stake with go into the load that the rock degree of depth confirms that single pile can bear.

Because it is different with general civilian construction that large-scale liquefied natural gas holds storage tank entirely, normally chooses reinforced concrete bored pile, to go into the rock degree of depth and be about 1 times of stake footpath, the stake footpath is selected 1.0m, 1.2m and 1.5m usually.

3, before the perfusion thickness of concrete cover of stake is checked, to guarantee that reinforcing bar is not corroded in the stake.

Because large-scale liquefied natural gas holds storage tank entirely and generally build the seashore in; Therefore need check the thickness of concrete cover of stake before the perfusion, to guarantee the interior reinforcing bar of stake be not corroded (concrete check process can be checked according to " concrete design specification ").

4, a preliminary definite stake number, the load that the full payload of promptly utilizing pile foundation to bear can bear divided by single pile obtains a number.

5, according to the loading characteristic of storage tank pile foundation, definite principle that lays out pile.

The principle that lays out pile comprises a type and pilespacing, and wherein, the stake type is: storage tank outermost two circles or three circle anchor ear shapes are arranged, and the cross layout of inner stake, a clump of piles is symmetric arrangement around the center.

Pilespacing

And require to satisfy S _aThe requirement of>=1.5d, d is the stake footpath.In storage tank cushion cap scope according to pilespacing S _aLay out pile, and suitably adjustment, the final figure that lays out pile obtained, storage tank cushion cap area

R _cBe storage tank cushion cap radius (R _c=storage tank radius R+3m).

Need consider also when laying out pile that the parameter of being correlated with comprises reinforcing bar, concrete parameter, each soil layer geomechanics parameter of ground, dead load load and the earthquake operating mode (OBE, SSE) of stake.Large-scale liquefied natural gas holds the storage tank pile foundation entirely and adopts reinforced concrete bored pile usually, and the minimum centers-distance between per two foundation piles generally is not less than 1.5 times of stake footpaths; When arranging foundation pile; Clump of piles bearing capacity point and the vertical permanent load application point of making a concerted effort of making a concerted effort is overlapped; And make foundation pile receive horizontal force and moment big module of anti-bending section to be arranged than general orientation; And decomposed rock was not less than 1 times of stake footpath during the stake end was gone into, and to bearing the outer ring stake of uplift force, going into the rock degree of depth needs to strengthen.

6, confirm the several safety conditions that satisfy of actual stake.

By the load of greatest axis power combination, the safety condition that stake number n need satisfy is:

$n\&GreaterEqual;\frac{V_0}{R_{\mathrm{ad}}}\&CenterDot;\mathrm{\&mu;}$

In the formula, μ is that the initial value of safety factor is 1.1, V ₀Be total vertical force, R _AdFor liquefied natural gas holds storage tank vertical bearing capacity of single pile characteristic value entirely.

7, under each operating mode, calculate and check the vertical bearing capacity of single pile,, then return step 6 and increase safety factor, confirm the stake number again, satisfy the checking computations requirement up to vertical bearing capacity of single pile if vertical bearing capacity of single pile does not satisfy the checking computations requirement.

When considering that pile crown is affixed, single-pile vertical orientation power V _D1And V _D2Can calculate by following formula:

V _d1,V _d2＝V ₀/n±{M ₀+(1+β×h)/(2×β)×H ₀}/Z _G

In the formula, V ₀Be total vertical force, unit is kN; V _D1Be the vertical force of single pile downward direction, V _D2Be the make progress vertical force of direction of single pile, n is a stake number; M ₀Be moment of flexure, unit is kNm; H ₀Be horizontal force, unit is kN; β is the stake characteristic value; H is a floor board framing outage degree; Z _GBe clump of piles section modulus, will be under different operating modes insert following table 1 through the value of the single-pile vertical orientation power that calculates:

The vertical force of table 1

Result of calculation from table 1 can draw, as the stake vertical force under each operating mode that calculates during less than the bearing capacity of single pile characteristic value: V _D1, V _D2<r _Ad, think that this pile foundation structurally is safe.

Load situation under each operating mode is shown in table 2～5:

Table 2 operate as normal load (kN)

* consider that partial safety factor for load is 1.4 (safety factor of employing).

Table 3 hydraulic pressure test load (kN)

* consider that partial safety factor for load is 1.2 (safety factor of employing).

Table 4OBE load

* the height in the table is the liquid level of counting from plate top surface;

Vertical force in the * table is horizontal seismic force and the vertically combination of seismic forces: 100% horizontal force+30% vertical force.

Table 5 SSE load

* the height in the table is the liquid level of counting from plate top surface;

Vertical force in the * table is horizontal seismic force and the vertically combination of seismic forces: 100% horizontal force+30% vertical force.

Like Fig. 2, shown in Figure 3, LNG tank vertical bearing capacity of single pile characteristic value R _Ad, clump of piles section modulus Z _G, stake characteristic value β and total vertical force V under each operating mode ₀, moment M ₀With horizontal force H ₀Computational process following:

(1) LNG tank vertical bearing capacity of single pile characteristic value R _AdFor:

R _ad＝R _ud/SF

R _ud＝R _f+R _P

In the formula, R _UdBe ultimate bearing capacity of single pile, unit is kN; SF is a safety factor, is taken as 2.0 usually under operate as normal, hydraulic pressure test, OBE, the SSE situation; R _fBe the maximum collateral resistance of stake, unit is kN, R _f=U * ∑ L _i* qsik, wherein U is the external diameter girth of stake, L _iBe the length of stake at i layer soil, qsik is the limit collateral resistance of stake; R _PBe bearing capacity of pile tip, unit is kN, R _P=qpk * A _P, wherein, A _PBe the stake end area, qpk is the extreme end resistance of stake.

(2) according to the difference of stake position, clump of piles section modulus Z _GFor:

$Z_G=\frac{\mathrm{\&Sigma;n}\&CenterDot;R_i^2}{R_{\max }}$

Outer ring stake and inner ring stake are calculated respectively, and wherein n is a number, R _iBe the peel off distance of pile center of i pile, R _MaxIt is the peel off distance of pile center of outmost turns stake.

(3) estimation equation of stake characteristic value β:

$\mathrm{\&beta;}=\sqrt[4]{(k_h\&times;d/4/E/I)}$

In the formula, the unit of β is m ^-1D is the diameter of stake, and E is the vertical modulus of elasticity (=27.0 * 10 of stake ⁶KN/m ²), I is stake second moment of area, wherein I=π d ⁴/ 64, k _hBe foundation soil horizontal reacting force coefficient; k _hOccurrence can search according to table 6.

Table 6

The soil layer type	kh(kN/m 3)×10 4
		Silt clay	0.28-1.4
Bury	1.4-2.8
		Clay	2.8-14
Stiff clay	14.0-
		Sand	2.8-8.3

(4) in the use of reality; In general seismic (seismal is the most dangerous; As long as the storage tank pile foundation is to satisfy security requirement, then must satisfy security requirement under other operating mode, so the present invention is through the relevant CALCULATION OF PARAMETERS of practical implementation instance explanation following of two kinds of different earthquake load working conditions under the seismic (seismal operating mode; Promptly under two kinds of different earthquake conditions of OBE and SSE, calculate vertical force, horizontal force and the moment of flexure of stake respectively.

The vertical force checking computations of stake need be considered seismic coefficient; Earthquake response spectrum calculated during the seismic coefficient of OBE and SSE was accused by the shake Commentary Report; Wherein vertical acceleration=0.65 * horizontal acceleration, large-scale liquefied natural gas hold the storage tank stake entirely when the high design of high liquid level, and concrete seismic coefficient is as shown in table 7:

Table 7 seismic coefficient

The horizontal force and the overturning moment of jar are as shown in table 8 in OBE and the SSE earthquake down, and both all can be definite through calculating by seismic coefficient, and base plate, exterior wall, top and interior jar of load action height are respectively h ₁, h ₂, h ₃, h _In

Table 8 horizontal force and overturning moment

Wherein, the vertical force of stake is 65% of a horizontal force.

The design formulas of the total vertical force of single pile is under the OBE situation:

V _{0, OBE}=V _{1, OBE}+ V _{2, OBE}+ V _{3, OBE}+ V _{In, OBE}

In the formula, base plate vertical force V _{1, OBE}For: V _{1, OBE}=α _{V, OBE}G ₁0.3+G ₁

Exterior wall vertical force V _{2, OBE}For: V _{2, OBE}=α _{V, OBE}G ₂0.3+G ₂

Concrete top vertical force V _{3, OBE}For: V _{3, OBE}=α _{V, OBE}G ₃0.3+G ₃

Interior jar of vertical force V _{In, OBE}For: V _{In, OBE}=α _{V, OBE}G _In0.3+G _In, wherein: α _{V, OBE}=0.65 α _{H, OBE}

The design formulas of aggregate level power is under the OBE situation:

H _{0, OBE}=H _{1, OBE}+ H _{2, OBE}+ H _{3, OBE}+ H _{In, OBE}

In the formula, base plate H _{1, OBE}Horizontal force is: H _{1, OBE}=α _{H, OBE}G ₁

Exterior wall horizontal force H _{2, OBE}For: H _{2, OBE}=α _{H, OBE}G ₂

Concrete top horizontal force H _{3, OBE}For: H _{3, OBE}=α _{H, OBE}G ₃

Interior jar of horizontal force H _{In, OBE}For: H _{In, OBE}=α _{H, OBE}(m _iG+G _In-mg)+α _{C, OBE}M _cG, wherein, impact mass m _iWith to current mass m _cRatio H by maximum operation liquid level and interior jar of radius R _L/ R obtains, H _L/ R is as shown in table 9:

Table 9m _i, m _cValue

H L/R	m i/m	m c/m
			0.3	0.176	0.824
0.5	0.300	0.700
			0.7	0.414	0.586
1.0	0.548	0.452
			1.5	0.686	0.314
2.0	0.763	0.237
			2.5	0.810	0.19
3.0	0.842	0.158

The heavy design formulas of total liquid is: $m=\frac{{\mathrm{\&pi;\; <figure-callout\; id="2"\; label="R"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">R</figure-callout>}}^2\&times;H_L\&times;\mathrm{\&rho;}}{1000}\left({10}^3\mathrm{Kg}\right)$

The design formulas of the total moment of flexure of OBE situation is:

M _{0, OBE}=M _{1, OBE}+ M _{2, OBE}+ M _{3, OBE}+ M _{In, OBE}

In the formula, the base plate moment M _{1, OBE}For: M _{1, OBE}=α _{H, OBE}G ₁H ₁

The exterior wall moment M _{2, OBE}For: M _{2, OBE}=α _{H, OBE}G ₂H ₂

Concrete bending square M _{3, OBE}For: M _{3, OBE}=α _{H, OBE}G ₃H ₃

Interior jar moment M _{In, OBE}For: M _{In, OBE}=α _{H, OBE}(m _iGh _i+ G _Inh _In-mgh _In)+α _{C, OBE}M _cGh _c, impact mass wording depth h wherein _iWith convection current mass action height h _cCan operate the ratio H of liquid level and interior jar of radius R by maximum _L/ R tables look-up and 10 obtains.

Table 10h _i, h _cValue

H L/R	h i/H L	h c/H L	H L/R	h i/H L	h c/H L
						0.3	0.400	0.521	1.5	0.439	0.690
0.5	0.400	0.543	2.0	0.448	0.751
						0.7	0.401	0.571	2.5	0.452	0.794
1.0	0.419	0.616	3.0	0.453	0.825

The design formulas of vertical force under the SSE situation:

V _{0, SSE}=V _{1, SSE}+ V _{2, SSE}+ V _{3, SSE}+ V _{In, SSE}

In the formula, base plate vertical force V _{1, SSE}For: V _{1, SSE}=α _{V, SSE}G ₁0.3+G ₁

Exterior wall vertical force V _{2, SSE}For: V _{2, SSE}=α _{V, SSE}G ₂0.3+G ₂

Concrete top vertical force V _{3, SSE}For: V _{3, SSE}=α _{V, SSE}G ₃0.3+G ₃

Interior jar of vertical force V _{In, SSE}For: V _{In, SSE}=α _{V, SSE}G _In0.3+G _In, α wherein _{V, SSE}=0.65 α _{H, SSE}

The design formulas of aggregate level power under the SSE situation:

H _{0, SSE}=H _{1, SSE}+ H _{2, SSE}+ H _{3, SSE}+ H _{In, SSE}

In the formula, floor level power H _{1, SSE}Design formulas be: H _{1, SSE}=α _{H, SSE}G ₁

Exterior wall horizontal force H _{2, SSE}For: H _{2, SSE}=α _{H, SSE}G ₂

Concrete top horizontal force H _{3, SSE}For: H _{3, SSE}=α _{H, SSE}G ₃

Interior jar of horizontal force H _{In, SSE}For: H _{In, SSE}=α _{H, SSE}(m _iG+G _In-mg)+α _{C, SSE}M _cG, wherein impact mass m _iWith to current mass m _cRatio by maximum operation liquid level and interior jar of radius R can be looked into above-mentioned table 9.

The design formulas of total moment of flexure under the SSE situation:

V _{0, SSE}=V _{1, SSE}+ V _{2, SSE}+ V _{3, SSE}+ V _{In, SSE}

In the formula, the base plate moment M ₁For: M ₁=α _{H, SSE}G ₁H ₁

The exterior wall moment M ₂For: M ₂=α _{H, SSE}G ₂H ₂

Concrete bending square M ₃For: M ₃=α _{H, SSE}G ₃H ₃

Interior jar moment M _InFor: M _In=α _{H, SSE}(m _iGh _i+ G _Inh _In-mgh _In)+α _{C, SSE}M _cGh _c

Impact mass wording depth h wherein _iWith convection current mass action height h _cCan look into above-mentioned table 10 with the ratio of interior jar of radius R.

(6) the concrete structure static load is calculated

The formula that concrete structure calculates unit weight is:

Prestressed concrete: Y _PC=24.5kN/m ³

Steel concrete: Y _RC=24.0kN/m ³

Based on above unit weight, the concrete structure static load is calculated like table 11:

Table 11 concrete structure static load

	Weight (kN)
		Base plate	G 1
Exterior wall	G 2
		The steel concrete top	G 3

8, horizontal bearing capacity of single pile checking computations if horizontal bearing capacity of single pile does not satisfy the checking computations requirement, are then returned step 6 and are increased safety factor, confirm the stake number again, satisfy the checking computations requirement up to horizontal bearing capacity of single pile.

Horizontal bearing capacity of single pile characteristic value R _HaFor:

$R_{\mathrm{ha}}=0.75\frac{{{\mathrm{\&alpha;}}_H}^3\mathrm{EI}}{v_x}{\mathrm{\&chi;}}_{\mathrm{oa}}$

In the formula, EI is the pile body bending rigidity; χ _OaFor the stake top allows horizontal movement; α _HHorizontal distortion coefficient for stake; v _xBe stake top horizontal movement coefficient.

Table 12 top (body) maximal bending moment coefficient v _mWith stake top horizontal movement coefficient v _x

During efficiency of pile groups that consideration is produced by cushion cap, pile group, soil phase mutual effect,

R _h=η _hR _Ha(R _hBe clump of piles horizontal bearing capacity)

Consider geological process and S _a/ d≤6 o'clock: η _h=η _iη _r+ η _l

${\mathrm{\&eta;}}_i={\left(\frac{\frac{S_a}{d}}{0.15n_1+0.10{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">n</figure-callout>}}_2+1.9}\right)}^{0.015{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">n</figure-callout>}}_2+0.45}$

${\mathrm{\&eta;}}_l=\frac{m_H\&CenterDot;{\mathrm{\&chi;}}_{\mathrm{oa}}\&CenterDot;B_c^{\&prime;}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="h\; c"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">h</figure-callout>}}_c^{}}{2\&CenterDot;n_1\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">n</figure-callout>}}_2\&CenterDot;R_{\mathrm{ha}}}$

When not considering geological process:

η _h＝η _iη _r+η _l+η _b

${\mathrm{\&eta;}}_b=\frac{{\mathrm{\&mu;}}_L\&CenterDot;P_c}{n_1\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">n</figure-callout>}}_2\&CenterDot;R_{\mathrm{ha}}}$

B′ _c＝B _c+1

P _c＝η _cf _ak(A-nA _ps)

In the formula, η _hBe efficiency of pile groups coefficient of colligation, η _iThe effect coefficient that influences each other for stake; η _rFor stake top effect of restraint coefficient, press table 13 value; η _lBe cushion cap side direction earth resistance effect coefficient; η _bBe frictional resistance effect coefficient at the bottom of the cushion cap; S _a/ d is the pitch to diameter ratio along the horizontal loading direction; n ₁, n ₂For being respectively along the stake number in horizontal loading direction and the every campshed of vertical-horizontal load direction; χ _OaFor stake top (cushion cap) horizontal movement permissible value, generally get 10mm; B ' _cFor cushion cap receives side direction earth resistance molded breadth on one side; B _cBe the cushion cap width; h _cBe the cushion cap height; H is the embedded depth of stake; μ _LFor at the bottom of the cushion cap and the friction factor between basic soil, can be by table 14 value; P _cThe vertical total load standard value of sharing for foundation soil at the bottom of the cushion cap; η _cCan be by table 15 value; A is the cushion cap gross area; A _PsBe the pile body section area.

Table 13 a top effect of restraint coefficient η _r

Conversion degree of depth α Hh	2.4	2.6	2.8	3.0	3.5	≥4.0
							Displacement control	2.58	2.34	2.20	2.13	2.07	2.05
Strength control	1.44	1.57	1.71	1.82	2.00	2.07

At the bottom of table 14 cushion cap and the coefficientoffriction between basic soil _L

Table 15 Pile Cap Effect coefficient η _c

Work as γ ₀H _i＜η _hR _HaThe time, satisfy stake horizontal force checking computations requirement, wherein γ ₀H _iBe to calculate the suffered horizontal force of stake, wherein, γ ₀Be the structural safety coefficient; η _hR _HaBe the horizontal bearing capacity that stake itself is had, as long as proof γ ₀H _i＜η _hR _HaThen the explanation stake has enough suffered horizontal forces of ability opposing, explains that the structure of stake horizontal direction is safe.

Wherein, the CALCULATION OF PARAMETERS process is in the horizontal bearing capacity of single pile characteristic value:

(1) pile foundation stake top horizontal loading design load

$H_i=\frac{H_0}{n}$

(2) the horizontal distortion alpha of stake _H

${\mathrm{\&alpha;}}_H=\sqrt[5]{\frac{m_{\mathrm{<figure-callout\; id="0"\; label="H\; b"\; filenames="HDA00001678276700022.png,HDA00001678276700032.png"\; state="\{\{state\}\}">H</figure-callout>}}{b}_{}{}_0}{\mathrm{EI}}}$

In the formula, m _HFactor of proportionality for the horizontal resistance coefficient of stake side soil; EI is the pile body bending rigidity, for reinforced concrete pile, and EI=0.85E _cI, E _cBe modulus of elasticity of concrete, I is a second moment of area.

b ₀Be the molded breadth of pile body, unit is m:

When circular stake is selected in stake: when diameter d≤1m, b ₀=0.9 (15d+0.5);

When diameter d＞1m, b ₀=0.9 (d+1);

When barrette is selected in stake: when hem width b≤1m, b ₀=1.5b+0.5;

When hem width b＞1m, b ₀=b+1.

9, the resistance to plucking checking computations are carried out in the stake of bearing uplift resistance,, then returned step 6 and increase safety factor, confirm the stake number again, up to satisfying the checking computations requirement if the resistance to plucking checking computations do not meet the demands.

According to single-pile vertical orientation power formula: V _D1, V _D2=V ₀/ n ± { M ₀+ (1+ β * h)/(2 * β) * H ₀}/Z _G

Work as V _D2Calculated value be on the occasion of the time, the foundation pile no pull out force that only is stressed is described, need not carry out the resistance to plucking checking computations to foundation pile this moment;

Work as V _D2When calculated value is negative value, explain that pull out force appears in foundation pile, need carry out the resistance to plucking checking computations this moment to foundation pile, and the resistance to plucking check formula is following:

V _d2≤T _uk/2+G _p

T _uk＝∑λ _iq _siku _il _i

G _p=γ _Concreteπ d ²l _i/ 4

In the formula: T _UkBe foundation pile resistance to plucking ultimate bearing capacity standard value; G _pBe the foundation pile deadweight; u _iFor the pile body girth, get u _i=π d; q _SikBe stake side surface i layer soil resistance to compression limit collateral resistance standard value; l _iFor stake long; λ _iBe resistance to plucking coefficient, γ _ConcreteBe concrete severe, can be by table 16 value.

Table 16 resistance to plucking coefficient lambda

Great soil group	The λ value
		Sand	0.50～0.70
Cohesive soil, silt	0.70～0.80

10, according to actual engineering geology type; Calculate the tank foundation settling amount of friction pile and socketed pile respectively, and compare, if greater than the regulation settling amount with the storage tank sedimentation ormal weight of engine request; Then return step 6 and increase safety factor; Again confirm a stake number, satisfy checking computations up to the tank foundation settling amount of friction pile and socketed pile and require (the storage tank sedimentation ormal weight of engine request can be chosen 40mm, perhaps in the light of actual conditions chooses); Wherein, the calculating of the tank foundation settling amount of friction pile and socketed pile is respectively:

(1) calculates the friction pile settling amount

1. subsidiary stress is calculated

G _k＝γ _G·A·d

$p=\frac{N_{\max }+G_k}{A}$

$p_{\mathrm{cz}}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&gamma;}}_i{d}_i$

p ₀＝p-p _cz

In the formula: γ _GFor stake soil severe, be taken as 20kN/m ³A is the cushion cap area, and unit is m ²P is a stake end average pressure, and unit is kPa; G _kBe the earthing weight more than the pile body, N _MaxBe maximum vertical load, p _CzBe gravity pressure at the bottom of the stake, unit is kPa; p ₀Be additonal pressure at the bottom of the stake, unit is kPa.

2. confirm settlement calculation degree of depth Z _n

Z _n＝b(2.5-0.4lnb)

In the formula, b calculates the length of side for the entity pile foundation.

3. settling amount calculates

During the sedimentation of circle pile foundation mid point, calculating pile foundation settlement amount is:

$s=\mathrm{\&psi;}\&CenterDot;{\mathrm{\&psi;}}_e\&CenterDot;s^{\&prime;}=\mathrm{\&psi;}\&CenterDot;{\mathrm{\&psi;}}_e\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="p"\; filenames="HDA00001678276700022.png,HDA00001678276700032.png"\; state="\{\{state\}\}">p</figure-callout>}}_0\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{z_i{\stackrel{\&OverBar;}{\mathrm{\&alpha;}}}_i-z_{i-1}{\stackrel{\&OverBar;}{\mathrm{\&alpha;}}}_{i-1}}{E_{\mathrm{si}}}$

${\mathrm{\&psi;}}_e={\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA00001678276700022.png,HDA00001678276700032.png"\; state="\{\{state\}\}">C</figure-callout>}}_0+\frac{n_b-1}{C_1(n_b-1)+{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}$

$n_b=\sqrt{n\&CenterDot;B_c/L_c}$

In the formula, p ₀Be the average additional stress at the bottom of cushion cap under the accurate permanent combination of load effect;

Be average additional stress coefficient, according to z/r rectangular aspect ratio a/b and depth-to-width ratio, wherein z=h is that stake is long, and r=d/2 is the cushion cap radius; C ₀, C ₁, C ₂For according to clump of piles pitch to diameter ratio S _a/ d, draw ratio l/d and basic aspect ratio L _c/ B _c, select for use by " technical code for building pile foundation " appendix E; L _c, B _c, n is respectively length and width (the corresponding circular cushion cap L of rectangle cushion cap _c=B _c=D) and total amount of pile; E _SiModulus of compressibility for the soil of i layer below the equivalent action face; z _iBe soil depth, i.e. h _iψ _eBe the settlement calculation correction factor; ψ is that pile foundation settlement calculates empirical coefficient, is confirmed by table 17.

Table 17 pile foundation settlement calculates empirical coefficient ψ

is the equivalent value of modulus of compressibility in the settlement calculation depth bounds, and design formulas is following:

${\stackrel{\&OverBar;}{E}}_s=\mathrm{\&Sigma;}{A}_i/\mathrm{\&Sigma;}\frac{A_i}{E_{\mathrm{si}}}$

$A_i=z_i{\stackrel{\&OverBar;}{\mathrm{\&alpha;}}}_i-z_{i-1}{\stackrel{\&OverBar;}{\mathrm{\&alpha;}}}_{i-1}$

A in the formula _iBe the integrated value of i layer soil additional stress coefficient, can be similar to and press the calculating of piecemeal area that ψ can basis along soil thickness The interior value of inserting.When the pile foundation out-of-shape, can adopt equivalent rectangular area to calculate pile foundation equivalence sedimentation coefficient, the length-width ratio of equivalent rectangular can be confirmed based on cushion cap actual size and shape.

(2) as shown in Figure 4, calculate the socketed pile settling amount

Socketed pile subsidence curve match sketch map can be got according to the engineering measurement data, subsidence curve rear portion fitting a straight line equation (the settling amount design formulas of socketed pile) as follows can be got by Fig. 4:

$S=(\mathrm{\&sigma;}-{\mathrm{<figure-callout\; id="4"\; label="q\; st"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{st}}\frac{4\mathrm{\&zeta;}{H}_t}{d})(\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}+\frac{H_t}{E_c})$

$\mathrm{\&sigma;}=V_{d1}/(\frac{\mathrm{\&pi;}}{4}\&CenterDot;d^2)$

In the formula: S is stake top sedimentation (mm); σ is a stake top stress (MPa); q _StBe stake side soil layer standard side friction; ζ is a soil layer side friction coefficient; E _cBe the pile concrete modulus of elasticity; H _tBe the last overburden layer degree of depth; D is a pile body diameter; K ₂Be embedding rock section stiffness factor (MPa/mm).

Like Fig. 5, shown in Figure 6, carry out statistical analysis to simplifying computation model parameter ζ, find that soil layer side friction coefficient ζ is relevant with the last overburden layer degree of depth, through statistics and correlation analysis, obtain ζ and last overburden layer depth relationship (as shown in Figure 5) as follows:

ζ＝1.3445-0.01975H _t

In like manner, to the simplified model parameter K ₂Carry out statistical analysis, find embedding rock section global stiffness COEFFICIENT K ₂Relevant with the embedding rock degree of depth, through statistics and correlation analysis, obtain K ₂With embedding rock depth relationship (as shown in Figure 6) as follows:

K ₂＝(0.2114H _w/d-0.09711)/d。

11, according to pile body internal force formula friction pile and socketed pile are carried out Reinforcement Calculation respectively, obtain the area of reinforcement A of single pile reinforcing bar _s(section area of longitudinal reinforcement), and further confirm the quantity of the required reinforcing bar of single pile.

As shown in Figure 7, adopt following three formula (pile body internal force formula) to calculate the number of steel bars of the required configuration of single pile, concrete computational process:

$N\&le;{\mathrm{\&alpha;\&alpha;}}_1{f}_c{\mathrm{\&pi;r}}^2(1-\frac{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;\&alpha;}}{2\mathrm{\&pi;\&alpha;}})+(\mathrm{\&alpha;}-{\mathrm{\&alpha;}}_t)f_y{A}_s---\left(1\right)$

$M\&le;\frac{2}{3}{\mathrm{\&alpha;}}_1{f}_c{r}^3{\sin }^3\mathrm{\&pi;\&alpha;}+f_y{A}_s{r}_s\frac{\sin \mathrm{\&pi;\&alpha;}+\sin \mathrm{\&pi;}{\mathrm{\&alpha;}}_t}{\mathrm{\&pi;}}---\left(2\right)$

α _t＝1.25-2α （3）

Can calculate α, α by formula (1)～(3) _tAnd A _s

Wherein, N=V _D1, H=H ₀/ n, M are the pile body moment of flexure; f _cBe concrete crushing strength design load, f _yBe longitudinal reinforcement tensile strength design load; R is the stake section radius, and unit is mm; r _sBe the radius of longitudinal reinforcement center of gravity place circumference, generally selected r _s=r-50, the mm of unit; α is corresponding to the ratio of the central angle of pressure zone concrete section area (rad) with 2 π; α _tBe longitudinal tensile area of reinforcement and whole ratio of longitudinal reinforcement section area, when α＞0.625, get α _i=0; α ₁Be coefficient, when strength grade of concrete is no more than C50, α ₁Be taken as 1.0, when strength grade of concrete is C80, α ₁Get 0.94, confirm by linear interpolation.

When friction pile carries out Reinforcement Calculation; In

formula; Z is the distance that cross section to ground is calculated in stake; H is a top horizontal loading, calculates the soil spring stiffness K of pile foundation according to the m method that provides in the ground basic norm:

K＝ab ₁mz

In the formula, a is each soil thickness; b ₁It is the molded breadth of stake; M is the factor of proportionality of foundation soil; Z is the distance of each soil layer mid point apart from ground;

When socketed pile carries out Reinforcement Calculation, M=0.0655f _RkD (0.7h) ², in the formula, f _RkBe the saturated single shaft compressive strength standard of rock value, unit is kpa, and h is that the rock degree of depth is gone in stake.

According to construction requirement, can pile body be divided into 3 sections arrangements of reinforcement along total length, get stake upper end 5m part and carry out arrangement of reinforcement according to the friction pile moment of flexure, get bottom 5m part by the socketed pile calculation of Bending Moment, mid portion is according to z=5m place calculation of Bending Moment.

And require to satisfy " technical code for building pile foundation " regulation:

N≤ψ _cf _cA _ps+0.9f′ _yA′ _s

In the formula, f _cBe concrete axial compressive strength design load; A _PsBe the stake section area; F ' _yBe lengthways main steel bar compressive strength design load; A ' _sBe the lengthways main steel bar section area; ψ _cFor foundation pile pile-formation process coefficient, press table 18 value.

Table 18 foundation pile pile-formation process coefficient ψ _c

The shear-carrying capacity formula that has only the square-section in " Code for design of concrete structures ", according to research, can derive circular cross-section shear-carrying capacity formula by the square-section design formulas:

$V\&le;\frac{{3\mathrm{\&pi;<figure-callout\; id="2"\; label="r"\; filenames="HDA00001678276700032.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}{4}{f}_t+\frac{\mathrm{\&pi;r}{A}_{\mathrm{sv}1}{f}_{\mathrm{yv}}}{s}$

Wherein: $V=\frac{H_0}{n}$

Therefrom can obtain hoop stirrup area A _Sv/ s=2A _Sv1/ s evenly joins hoop along the pile body total length.

In the formula, r is stake section radius, i.e. d/2; A _Sv1Sectional area for single stirrup; S is a stirrup spacing; f _tBe concrete axial tensile strength design load; f _YvBe stirrup tensile strength design load.

12, lay out pile according to the stake number and the area of reinforcement, accomplish the making of foundation pile.

Above-mentioned each embodiment only is used to explain the present invention, and wherein step of preparation method etc. all can change to some extent, and every equivalents of on the basis of technical scheme of the present invention, carrying out and improvement all should not got rid of outside protection scope of the present invention.

Claims (9)

1. a large-scale liquefied natural gas holds the preparation method of storage tank pile foundation entirely, may further comprise the steps:

1) holds the weight and the external condition of storage tank entirely according to the large-scale liquefied natural gas of the required carrying of reality, confirm to wait to make the required full payload of bearing of pile foundation;

2) select a stake type, and based on the stake footpath of selected stake with go into the load that the rock degree of depth confirms that single pile can bear;

3) before the perfusion thickness of concrete cover of stake is checked, to guarantee that reinforcing bar is not corroded in the stake;

4) full payload of utilizing pile foundation to bear tentatively obtains a number divided by the load that single pile can bear;

5) confirm the principle that lays out pile;

6) confirm the several safety conditions that satisfy of actual stake

In the formula, n is the stake number, and μ is a safety factor, V ₀Be total vertical force, R _AdFor liquefied natural gas holds storage tank vertical bearing capacity of single pile characteristic value entirely;

7) under each operating mode, calculate and check the vertical bearing capacity of single pile, as the vertical bearing capacity of single pile that calculates during: V less than the bearing capacity of single pile characteristic value _D1, V _D2<r _Ad, think that this vertical carrying structurally is safe, then gets into step 8); If vertical bearing capacity of single pile does not satisfy the checking computations requirement, then return step 6) and increase safety factor, confirm the stake number again, satisfy the checking computations requirement up to vertical bearing capacity of single pile, wherein, V _D1And V _D2Be single-pile vertical orientation power, R _AdFor liquefied natural gas holds storage tank vertical bearing capacity of single pile characteristic value entirely;

8) horizontal bearing capacity of calculating and check single pile under each operating mode is worked as γ ₀H _i＜η _hR _Ha, think that horizontal bearing capacity of single pile satisfies the checking computations requirement, get into step 9), if horizontal bearing capacity of single pile does not satisfy the checking computations requirement, then return step 6) and increase safety factor, confirm the stake number again, satisfy the checking computations requirement up to horizontal bearing capacity of single pile, wherein, γ ₀H _iBe to calculate the suffered horizontal force of single pile, η _hR _HaIt is the horizontal bearing capacity that stake itself is had;

9) the resistance to plucking checking computations are carried out in the stake of bearing uplift resistance,, then returned step 6), increase safety factor, readjust a number,, then get into step 10) up to satisfying the checking computations requirement if the resistance to plucking checking computations do not meet the demands;

10) based on actual engineering geology type; Calculate the tank foundation settling amount of friction pile and embedded rock pile respectively, the sedimentation value of stipulating with actual engine request compares, if greater than the sedimentation value of stipulating; Then return step 6) and increase safety coefficient; Again confirm a stake number, satisfy the checking computations requirement, the entering step 11) up to the tank foundation settling amount of friction pile and embedded rock pile;

11) according to pile body internal force formula friction pile and socketed pile are carried out Reinforcement Calculation respectively, obtain the reinforcing bar area of reinforcement A of single pile _s, and further obtain the required number of steel bars of single pile, and wherein, A _sBe through Find the solution and obtain, in the formula, M is the pile body moment of flexure, f _cBe concrete crushing strength design load, f _yBe longitudinal reinforcement tensile strength design load, r is the stake section radius, r _sBe the radius of longitudinal reinforcement center of gravity place circumference, α is corresponding to the central angle of pressure zone concrete section area and the ratio of 2 π, α ₁Be coefficient, α _tBe the ratio of longitudinal tensile area of reinforcement with whole longitudinal reinforcement section area;

12) lay out pile according to the stake number and the area of reinforcement, accomplish the making of foundation pile.

2. a kind of large-scale liquefied natural gas as claimed in claim 1 holds the preparation method of storage tank pile foundation entirely; It is characterized in that: the said step 5) principle of confirming to lay out pile comprises lay out pile shape and pilespacing; Wherein, The shape that lays out pile is that storage tank outermost two circles or three circle anchor ear shapes are arranged, the cross layout of inner stake, and a clump of piles is symmetric arrangement around the center; Pilespacing

At storage tank cushion cap radius is R _cThe storage tank cushion cap in according to S _aLay out pile, n is the stake number, storage tank cushion cap area $A_c=\frac{\mathrm{\&pi;}{R}_c^2}{4}.$

3. according to claim 1 or claim 2 a kind of large-scale liquefied natural gas holds the preparation method of storage tank pile foundation entirely, and it is characterized in that: single-pile vertical orientation power is in the said step 7):

V _d1,V _d2＝V ₀/n±{M ₀+(1+β×h)/(2×β)×H ₀}/Z _G，

In the formula, V ₀Be total vertical force, n is the stake number, M ₀Be moment of flexure, H ₀Be horizontal force, β is the stake characteristic value, and h is a floor board framing outage degree, Z _GBe clump of piles section modulus, wherein,

D is the diameter of stake, and E is the vertical modulus of elasticity of stake, and I is the stake second moment of area, k _hBe foundation soil horizontal reacting force coefficient;

R _iBe the peel off distance of pile center of i pile, R _MaxIt is the peel off distance of pile center of outmost turns stake.

4. a kind of large-scale liquefied natural gas as claimed in claim 3 holds the preparation method of storage tank pile foundation entirely, it is characterized in that: said moment M ₀Comprise two kinds of situation: based on total moment M of OBE situation _{0, OBE}With total moment of flexure V based on the SSE situation _{0, SSE}Wherein, M _{0, OBE}=M _{1, OBE}+ M _{2, OBE}+ M _{3, OBE}+ M _{In, OBE}, in the formula, M _{1, OBE}Be base plate moment of flexure, M _{2, OBE}Be exterior wall moment of flexure, M _{3, OBE}Be concrete bending square, M _{3, OBE}Be concrete bending square, M _{In, OBE}Be interior jar of moment of flexure; V _{0, SSE}=V _{1, SSE}+ V _{2, SSE}+ V _{3, SSE}+ V _{In, SSE}, V _{1, SSE}Be base plate vertical force, V _{2, SSE}Be exterior wall vertical force, V _{3, SSE}Be concrete top vertical force, V _{In, SSE}Be interior jar of vertical force.

5. hold the preparation method of storage tank pile foundation entirely like claim 1 or 2 or 4 described a kind of large-scale liquefied natural gas, it is characterized in that: the tank foundation settling amount of socketed pile is in the said step 10):

$S=(\mathrm{\&sigma;}-q_{\mathrm{st}}\frac{4\mathrm{\&zeta;}{H}_t}{d})(\frac{1}{K_2}+\frac{H_t}{E_c})$

$\mathrm{\&sigma;}=V_{d1}/(\frac{\mathrm{\&pi;}}{4}\&CenterDot;d^2)$

In the formula, S is stake top sedimentation; σ is a stake top stress; q _StBe stake side soil layer standard side friction; ζ is a soil layer side friction coefficient; E _cBe the pile concrete modulus of elasticity; H _tBe the last overburden layer degree of depth; D is the diameter of stake; K ₂Be embedding rock section stiffness factor, wherein, ζ and last overburden layer depth relationship are: ζ=1.3445-0.01975H _t, K ₂With embedding rock depth relationship be: K ₂=(0.2114H _w/ d-0.09711)/d.

6. a kind of large-scale liquefied natural gas as claimed in claim 3 holds the preparation method of storage tank pile foundation entirely, it is characterized in that: the tank foundation settling amount of socketed pile is in the said step 10):

$S=(\mathrm{\&sigma;}-q_{\mathrm{st}}\frac{4\mathrm{\&zeta;}{H}_t}{d})(\frac{1}{K_2}+\frac{H_t}{E_c})$

$\mathrm{\&sigma;}=V_{d1}/(\frac{\mathrm{\&pi;}}{4}\&CenterDot;d^2)$

In the formula, S is stake top sedimentation; σ is a stake top stress; q _StBe stake side soil layer standard side friction; ζ is a soil layer side friction coefficient; E _cBe the pile concrete modulus of elasticity; H _tBe the last overburden layer degree of depth; D is the diameter of stake; K ₂Be embedding rock section stiffness factor, wherein, ζ and last overburden layer depth relationship are: ζ=1.3445-0.01975H _t, K ₂With embedding rock depth H _wFor the horizontal shear force relation is: K ₂=(0.2114H _w/ d-0.09711)/d.

7. hold the preparation method of storage tank pile foundation like claim 1 or 2 or 4 or 6 described a kind of large-scale liquefied natural gas entirely, it is characterized in that: the area of reinforcement A of friction pile in the said step 11) _sIn the calculating,

Wherein, K=ab ₁Mz, a are each soil thickness; b ₁It is the molded breadth of stake; M is the factor of proportionality of foundation soil; Z is the distance of each soil layer mid point apart from ground, and l is that stake is long, and H is a top horizontal loading; In the Reinforcement Calculation of socketed pile, M=0.0655f _RkD (0.7h) ², in the formula, f _RkBe the saturated single shaft compressive strength standard of rock value, h is that the rock degree of depth is gone in stake, and d is the stake footpath.

8. a kind of large-scale liquefied natural gas as claimed in claim 3 holds the preparation method of storage tank pile foundation entirely, it is characterized in that: the area of reinforcement A of friction pile in the said step 11) _sIn the calculating,

Wherein, K=ab ₁Mz, a are each soil thickness; b ₁It is the molded breadth of stake; M is the factor of proportionality of foundation soil; Z is the distance of each soil layer mid point apart from ground, and l is that stake is long, and H is a top horizontal loading; In the Reinforcement Calculation of socketed pile, M=0.0655f _RkD (0.7h) ², in the formula, f _RkBe the saturated single shaft compressive strength standard of rock value, h is that the rock degree of depth is gone in stake, and d is the stake footpath.

9. a kind of large-scale liquefied natural gas as claimed in claim 5 holds the preparation method of storage tank pile foundation entirely, it is characterized in that: the area of reinforcement A of friction pile in the said step 11) _sIn the calculating,

Wherein, K=ab ₁Mz, a are each soil thickness; b ₁It is the molded breadth of stake; M is the factor of proportionality of foundation soil; Z is the distance of each soil layer mid point apart from ground, and l is that stake is long, and H is a top horizontal loading; In the Reinforcement Calculation of socketed pile, M=0.0655f _RkD (0.7h) ², in the formula, f _RkBe the saturated single shaft compressive strength standard of rock value, h is that the rock degree of depth is gone in stake, and d is the stake footpath.

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