CN110344388A - The tamping point of dynamic compaction reinforced saturated sand foundation effectively influences line space design method - Google Patents
The tamping point of dynamic compaction reinforced saturated sand foundation effectively influences line space design method Download PDFInfo
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- E—FIXED CONSTRUCTIONS
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- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
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Abstract
The tamping point that the present invention provides a kind of dynamic compaction reinforced saturated sand foundation effectively influences line space design method, is related to reinforced soft soil ground technical field.This method acts on the solution that stress-strain relation, flow and the relationship of head loss of horizontal direction compression, the lower saturated sand foundation pore water pressure force function of strong rammer effect etc. occur for lower micro unit by strong rammer, and finally obtaining effectively influences distance computation formula by the saturated sand foundation horizontal direction of saturated sand foundation horizontal direction Dynamic response characteristic parameter, saturated sand foundation coefficient of horizontal consolidation, the strong rammer fluctuation strong rammer that the parameters such as ground acceleration amplitude peak caused by propagation time, strong rammer calculate in ground vibration generation.The present invention can objectively carry out the engineering design of strong rammer saturated sand foundation, and the examination for targetedly carrying out strong rammer engineering is rammed and detection work, improve engineering construction efficiency, reduce engineering cost.
Description
Technical field
The present invention relates to reinforced soft soil ground technical field more particularly to a kind of rammers of dynamic compaction reinforced saturated sand foundation
Point effectively influences line space design method.
Background technique
Currently, having carried out the test of dynamic compaction reinforced soft soil foundation, theory etc. research both at home and abroad, relate generally to be saturated
The soft soil foundation forced ramming reinforcing work of cohesive soil, unsaturated clay, unsaturation sand, remains at the statistics of empirical data
Stage.In mandatory specification " building foundation treatment technical specification (JGJ 79-2012) ", summarized according to field application situation
Effective reinforcement depth " effective reinforcement depth of table 6.3.3-1 strong rammer " is set fourth as " tamping point in specification in terms of the tamping point horizontal space
Spacing can use (2.5~3.5) times of hammer ram diameter ", the horizontal direction of Investigation of Soft Subgrade Reinforcement by Dynamic Compaction is not provided in other documents yet
Tamping point line space design method.With extensive application of the sea sand hydraulic reclamation in islands and reefs, the construction of coastal waters beach in recent years, due to heavy-tamping method
Reinforce that the saturated sand foundation construction time is short, remarkable in economical benefits, application is more extensive, but reliable without forming science
Design method, relies solely on examination and rams to test and determine that parameter blindness is larger, higher cost, it is therefore necessary to propose a kind of heavy-tamping method
The tamping point for reinforcing saturated sand foundation effectively influences the design method of spacing.
Summary of the invention
The technical problem to be solved by the present invention is in view of the above shortcomings of the prior art, provide a kind of dynamic compaction reinforced saturation
The tamping point of sand foundation effectively influences line space design method, can quickly and effectively determine dynamic compaction reinforced saturated sand foundation
Tamping point effectively influences spacing.
In order to solve the above technical problems, the technical solution used in the present invention is:
A kind of tamping point of dynamic compaction reinforced saturated sand foundation effectively influences line space design method, and this method assumes saturated sand
Soil is isotropic elastic material, and the flowing of pore water meets Darcy law, and the compressed coefficient is constant, is caused according to strong rammer
The critical pore pressure angle of saturated sand set out, consideration strong rammer mechanism is axisymmetric problem, the section of axis is taken, according to flat
Face Study on Problems establishes its theoretical model, and the specific method is as follows:
In saturated sand foundation, micro unit is chosen, horizontal direction stress is σx, horizontal direction soil skeleton stress is εx, strong
Under rammer effect, horizontal direction compression occurs for micro unit, and stress-strain relation is as follows,
In formula, αxFor the horizontal direction compressed coefficient of saturated sand foundation；E is the void ratio of sand foundation soil skeleton；Dx is
The direction micro unit x unit length；T is strong rammer action time in ground；
The seepage discharge and discharge section area and gross head for passing through porous media according to water in the unit time of Darcy's law
It loses directly proportional, is inversely proportional with percolation path length, establishes the relationship of flow and head loss, be shown below,
Qx=kxAxhx/Lx=kxAxix (2)
In formula, QxFor horizontal direction, that is, x-axis direction cross-section of river flows per unit time；kxFor the seepage coefficient of horizontal direction soil；
AxFor micro unit x-axis direction discharge section area；hxFor the loss of x-axis direction gross head；LxFor x-axis direction Porous Media road
The length of diameter；ixFor x-axis direction hydraulic gradient；
Changes in flow rate of the micro unit in the direction x is formula (3), indicates the unit area of a certain depth in saturated sand foundation
The surface in the direction micro unit x of upper, the unit time thickness d x flows in and out changes in flow rate；
It is assumed that the direction the x compressive deformation of saturated sand foundation micro unit is identical with pore water discharge rate, then there are formula (4),
Formula (4) are substituted into formula (1), are obtained
During strong rammer saturated sand foundation, it is believed that in tiny time section, solid particle skeleton and pore water pressure can
It is considered as static conditions, the stress of solid particle skeleton is solved using quasi-static model, while assumes the direction x, the direction z in tiny time
Pore water pressure in section is identical, then establishes the saturated sand infinitesimal body stress in the direction x, be shown below,
In formula, γ is saturated sand bulk density；σxFor the direction saturated sand micro unit x stress；k0For coefficient of static earth pressure；x
For saturated sand thickness；B is the strong rammer acceleration peak swing on saturated sand foundation ground；ω is the saturated sand under the conditions of strong rammer
The circular frequency of soil base, ω=2 π/T, T are the period；pfFor pore water pressure；
Formula (6) are substituted into formula (5), abbreviation arranges to obtain formula (7),
It is indicated in the hydraulic gradient of the micro unit that saturated sand foundation depth is z location, x-axis micro unit surfaces externally and internally are as follows:
In formula, γwFor underground water bulk density；
Formula (8) are substituted into formula (7), are enabledCvxFor the horizontal direction saturated sand foundation coefficient of consolidation, change
Letter, arrangement obtain the Second Order Nonhomogeneous partial differential equation of excess pore water pressure, are shown below,
Formula (9) are solved using the separation of variable, strong rammer is obtained and acts on lower saturated sand foundation pore water pressure force function, it is such as public
Shown in formula (18),
In formula, c1x、c2x、c3x、βxFor partial differential equation coefficient to be asked；
If strong rammer causes elastic wave to continue t=t1Time, the liquefaction that saturated sand foundation can be made z-depth occur are existing
As, then the direction z depth saturated sand foundation micro unit x pore water pressure dynamic balance, i.e.,
In formula, g is acceleration of gravity；
Work as t1→ ∞,
c3x=γ zg+ (1-k0)γzB sinωt (20)
When hammer ram not yet contacts saturated sand, i.e. when t=0, the saturated sand micro unit pore water pressure in the direction x is place
Pore water pressure original value, function are
At this point, at z-depth, x=0, pore water pressure zero, i.e.,
c1x=-γ zg (22)
At z-depth, x=l, there is densification shell in saturated sand foundation ground under the P wave effect of strong rammer, quiet on the outside of shell
Water voids water pressure and its internal saturated sand micro unit pore water pressure dynamic balance, then c2xSolution be
Formula (20), (22), (24) are substituted into formula (18),
Z-depth, x=l are substituted into formula (28), arranged
For the outer surface of the compression shell of saturated sand, at z-depth, micro unit horizontal direction pore water pressure is pf=γ
Zg, then
It enablesAnd sin ω t=1, it substitutes into formula (27), obtains single tamping point horizontal direction effectively and influence distance and be
In formula, JxFor saturated sand foundation horizontal direction Dynamic response characteristic parameter；CvxFor saturated sand foundation horizontal direction
The coefficient of consolidation；T is that strong rammer fluctuates the propagation time in ground；B is ground acceleration amplitude peak caused by strong rammer；G is gravity
Acceleration；X is that the saturated sand foundation horizontal direction that the vibration of single tamping point strong rammer generates effectively influences distance；
The saturated sand foundation horizontal direction that then strong rammer vibration generates effectively influences spacing X and is
When the material of hydraulic reclamation saturated sand foundation is relatively uniform, in formula (29), horizontal direction saturated sand foundation is solid
Clone number CvxIt is determined according to geotechnological consolidation test, horizontal direction Dynamic response characteristic parameter is selected by vertical Dynamic response characteristic parameter
It takes, ground acceleration amplitude peak B caused by strong rammer action time parameter t, strong rammer rams the vibration pickup number that test is laid according to examination
According to determination, parameter progress Preliminary design is read according to the survey that has for closing on place, close geological conditions.
The beneficial effects of adopting the technical scheme are that dynamic compaction reinforced saturated sand soil provided by the invention
The tamping point of base effectively influences line space design method, can objectively carry out the engineering design of strong rammer saturated sand foundation, be directed to
Property carry out strong rammer engineering examination ram and detection work, improve engineering construction efficiency, reduce engineering cost.
Specific embodiment
With reference to embodiment, the embodiment of the present invention is furthur described in detail.Following embodiment is used for
Illustrate the present invention, but is not intended to limit the scope of the invention.
The tamping point of the dynamic compaction reinforced saturated sand foundation of the present embodiment effectively influences line space design method institute specific as follows
It states.
It is assumed that saturated sand is isotropic elastic material, the flowing of pore water meets Darcy law, and the compressed coefficient is
Constant.It sets out according to the critical pore pressure angle of saturated sand caused by strong rammer, consideration strong rammer mechanism is axisymmetric problem, is taken
The section of axis, is studied according to plane problem, establishes its theoretical model.
In saturated sand foundation, micro unit is chosen, horizontal direction stress is σx, horizontal direction soil skeleton stress is εx, strong
Under rammer effect, horizontal direction compression occurs for micro unit, and stress-strain relation is as follows,
In formula, αxFor the horizontal direction compressed coefficient of saturated sand foundation；E is the void ratio of sand foundation soil skeleton；Dx is
The direction micro unit x unit length；T is strong rammer action time in ground.
The seepage discharge and discharge section area and gross head for passing through porous media according to water in the unit time of Darcy's law
It loses directly proportional, is inversely proportional with percolation path length, establishes the relationship of flow and head loss, see formula
Qx=kxAxhx/Lx=kxAxix (2)
In formula, QxFor horizontal direction, that is, x-axis direction cross-section of river flows per unit time；kxFor the seepage coefficient of horizontal direction soil；
AxFor micro unit x-axis direction discharge section area；hxFor the loss of x-axis direction gross head；LxFor x-axis direction Porous Media road
The length of diameter；ixFor x-axis direction hydraulic gradient.
Changes in flow rate of the micro unit in the direction x is formula (3), indicates the unit area of a certain depth in saturated sand foundation
The surface in the direction x of the micro unit of upper, the unit time thickness d x flows in and out changes in flow rate.
It is assumed that the direction the x compressive deformation of saturated sand foundation micro unit is identical with pore water discharge rate, then formula can be established
(4),
Formula (4) are substituted into formula (1), are obtained
During strong rammer saturated sand foundation, it is believed that in tiny time section, solid particle skeleton and pore water pressure can
It is considered as static conditions, the stress of solid particle skeleton is solved using quasi-static model, while assumes the direction x, the direction z in tiny time
Pore water pressure in section is identical, then can establish the saturated sand infinitesimal body stress in the direction x, be shown below,
In formula, γ is saturated sand bulk density；σxFor the direction saturated sand micro unit x stress；k0For coefficient of static earth pressure；z
For saturated sand thickness；B is the strong rammer acceleration peak swing on saturated sand foundation ground；ω is the saturated sand under the conditions of strong rammer
The circular frequency of soil base, ω=2 π/T, T are the period；pfFor pore water pressure.
Formula (6) are substituted into formula (5), abbreviation arranges to obtain formula (7)
In the micro unit that saturated sand foundation depth is z location, the hydraulic gradient of x-axis micro unit surfaces externally and internally can be indicated
Are as follows:
In formula, γwFor underground water bulk density.
Formula (8) are substituted into formula (7), are enabledCvxFor the horizontal direction saturated sand foundation coefficient of consolidation, change
Letter, arrangement obtain the Second Order Nonhomogeneous partial differential equation of excess pore water pressure, are shown below,
Using separation of variable solution formula (9).If pore water pressure function can be expressed as
pf=X (x) T (t)+k0γzB sinωt+c (10)
Wherein, X (x), T (t) are respectively the horizontal influence function of strong rammer of pore water pressure, strong rammer action time function, and c is
Constant term；
Then,
Formula (11), (12) are substituted into formula (9), are obtained
Functional Analysis is carried out it is found that necessary and sufficient condition existing for equation is to formula (13)WithFor real constant.
In formula, βxDifferential equation coefficient to be asked.
Formula (14) and formula (15) are ODE, X (x), T (t) general solution be respectively as follows:
X (x)=c'1xcosβxx+c'2xsinβxx (16)
In formula, c '1x、c′2x、c′3xFor the undetermined coefficient of X (x), T (t) function.
Formula (16) and formula (17) are then substituted into formula (10), strong rammer is obtained and acts on lower saturated sand foundation pore water pressure
Force function is formula (18).
In formula, c1x、c2x、c3xFor partial differential equation coefficient to be asked.
If strong rammer causes elastic wave to continue t=t1Time, the liquefaction that saturated sand foundation can be made z-depth occur are existing
As, then the direction z depth saturated sand foundation micro unit x pore water pressure dynamic balance, i.e.,
In formula, g is acceleration of gravity；
Work as t1→ ∞,
c3x=γ zg+ (1-k0)γzB sinωt (20)
When hammer ram not yet contacts saturated sand, i.e. when t=0, the saturated sand micro unit pore water pressure in the direction x is place
Pore water pressure original value, function are
At this point, at z-depth, x=0, pore water pressure zero, i.e.,
c1x=-γ zg (22)
At z-depth, x=l, there is densification shell in saturated sand foundation ground under the P wave effect of strong rammer, quiet on the outside of shell
Water voids water pressure and its internal saturated sand micro unit pore water pressure dynamic balance, i.e. flowing pressure is zero,
C is solved by formula (23)2x, arrange, abbreviation obtain formula (24),
Formula (20), (22), (24) are substituted into formula (18),
Z-depth, x=l are substituted into formula (28), arranged
For the outer surface of the compression shell of saturated sand, at z-depth, micro unit horizontal direction pore water pressure is pf=γ
Zg, then
It enablesAnd sin ω t=1, it substitutes into formula (27), obtaining single tamping point horizontal direction effectively influences distance for public affairs
Formula (28).
In formula, JxFor saturated sand foundation horizontal direction Dynamic response characteristic parameter；CvxFor saturated sand foundation horizontal direction
The coefficient of consolidation；T is that strong rammer fluctuates the propagation time in ground；B is ground acceleration amplitude peak caused by strong rammer；G is gravity
Acceleration；X is that the saturated sand foundation horizontal direction that the vibration of single tamping point strong rammer generates effectively influences distance.
The saturated sand foundation horizontal direction that then strong rammer vibration generates effectively influences spacing X and is
When the material of hydraulic reclamation saturated sand foundation is relatively uniform, in formula (29), horizontal direction saturated sand foundation is solid
Clone number CvxIt is determined according to geotechnological consolidation test, horizontal direction Dynamic response characteristic parameter is selected by vertical Dynamic response characteristic parameter
It takes.Ground acceleration amplitude peak B caused by strong rammer action time parameter t, strong rammer rams the vibration pickup number that test is laid according to examination
According to determination, parameter progress Preliminary design can be read according to the survey that has for closing on place, close geological conditions.
In the present embodiment, the effective shadow of tamping point of strong rammer vibration is carried out to certain coastal area saturated sand soil using the above method
Line space design is rung, strong rammer Geological condition and construction parameter are as follows:
(1) strong rammer Geological condition
Certain coastal area saturated sand stratum is respectively from top to bottom:
Rinse fill: it is loose, it is light grey, it is mainly made of powder, fine sand, contains shell fragment, it is wet~very wet, it is underwater to be saturated.
Miscellaneous fill: it is loose, it is mainly made of clinker (part is flyash), crushed stone, queen closer, contains shell fragment, office
Portion contains concrete block.
Fine sand: ash~grey black, loose~slightly close, predominantly fine sand, is partially fine sand and flour sand alternating layers, feldspar~quartz
Matter, particle have stratification, saturation in sub- round, equal kernel structure, mica containing volume, shell, toughness soil interlayer.
Fine sand: ash~grey black, in close~closely knit, predominantly fine sand, be partially fine sand and flour sand alternating layers, feldspar~quartz
Matter, particle have stratification, saturation in sub- round, equal kernel structure, mica containing volume, shell, toughness soil interlayer.
Silt: grey, it is slightly close~in it is close, contain organic matter, shell fragment has a bad smell, and silty clay, flour sand are pressed from both sides in mulling
Thin layer is in mutual stratiform, saturation.
Fine sand: ash~grey black, it is slightly close~in close, predominantly fine sand, be partially fine sand and flour sand alternating layers, feldspar~quartz
Matter, particle is in sub- round, equal kernel structure, and containing about 25% cohesive soil, mica containing volume, shell, toughness soil interlayer has stratification,
Saturation.
Silty clay: grey black, it is plastic, contain shell fragment, organic matter, has bad smell, part contains silt and flour sand thin layer,
In mutual stratiform.
Fine sand: ash~grey black, in close~closely knit, predominantly fine sand, be partially fine sand and flour sand alternating layers, feldspar~quartz
Matter, particle have stratification, saturation in sub- round, equal kernel structure, mica containing volume, shell, toughness soil interlayer.
Silty clay: brown Huang~yellowish-brown, plastic~hard plastic contain iron oxide, mica, iron manganese concretion and gray bar.
Fine sand: sallow~taupe, closely knit, feldspar~quartziferous, equal kernel structure contain shell fragment, mix cohesive soil, layer
Reason, saturation.
1.5~2.0m of underground water buried depth during prospecting.
(2) strong punning design parameter and kinetic parameter are chosen
Hammer ram hammers weight 200kN into shape, falls away from 15m, floor space diameter 2.4m, hammers bottom projected area 4.522m into shape2, base pressure
44.23 kN/m2, tamping energy 3000kNm.
According to soil test, the ground consolidation coefficient (C of coastal area sandy soils to be reinforcedv) be 0.00324~
0.00383m2/s；It is about 0.8 second according to single-point examination rammer test measurement strong rammer fluctuation action time in ground.
For above-mentioned saturated sand soil, the tamping point using dynamic compaction reinforced saturated sand foundation provided in this embodiment is effective
Line space design method is influenced, the tamping point for calculating strong rammer saturated sand foundation effectively influences spacing and is shown in Table 1, wherein a/g is ground base table
The ratio of areal acceleration a and gravity acceleration g；X is that tamping point effectively influences spacing.
The tamping point of 1 forced ramming reinforcing saturated sand foundation of table effectively influences spacing
Effectively distance computation is influenced according to tamping point as a result, designing strong rammer tamping point design spacing is 7.0m, by scene examination rammer
It is detected after test and rammer, without influencing each other between tamping point, forced ramming reinforcing construction efficiency is improved, and eliminates the saturation of 6.5m depth bounds
Sand foundation Liquefaction, foundation strength meet design requirement, and construction cost is effectively reduced.
Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although
Present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: it still may be used
To modify to technical solution documented by previous embodiment, or some or all of the technical features are equal
Replacement；And these are modified or replaceed, model defined by the claims in the present invention that it does not separate the essence of the corresponding technical solution
It encloses.
Claims (1)
1. a kind of tamping point of dynamic compaction reinforced saturated sand foundation effectively influences line space design method, it is characterised in that: this method
It is assumed that saturated sand is isotropic elastic material, the flowing of pore water meets Darcy law, and the compressed coefficient is constant, is pressed
It sets out according to the critical pore pressure angle of saturated sand caused by strong rammer, consideration strong rammer mechanism is axisymmetric problem, takes axis
Section is studied according to plane problem, establishes its theoretical model, the specific method is as follows:
In saturated sand foundation, micro unit is chosen, horizontal direction stress is σx, horizontal direction soil skeleton stress is εx, make in strong rammer
Under, horizontal direction compression occurs for micro unit, and stress-strain relation is as follows,
In formula, αxFor the horizontal direction compressed coefficient of saturated sand foundation；E is the void ratio of sand foundation soil skeleton；Dx is micro unit
The direction x unit length；T is strong rammer action time in ground；
It is lost according to water in the unit time of Darcy's law by the seepage discharge and discharge section area and gross head of porous media
It is directly proportional, it is inversely proportional with percolation path length, establishes the relationship of flow and head loss, be shown below,
Qx=kxAxhx/Lx=kxAxix (2)
In formula, QxFor horizontal direction, that is, x-axis direction cross-section of river flows per unit time；kxFor the seepage coefficient of horizontal direction soil；AxFor
Micro unit x-axis direction discharge section area；hxFor the loss of x-axis direction gross head；LxFor x-axis direction Porous Media path
Length；ixFor x-axis direction hydraulic gradient；
Micro unit the direction x changes in flow rate be formula (3), indicate saturated sand foundation in a certain depth unit area on,
The surface in the direction micro unit x of the thickness d x of unit time flows in and out changes in flow rate；
It is assumed that the direction the x compressive deformation of saturated sand foundation micro unit is identical with pore water discharge rate, then there are formula (4),
Formula (4) are substituted into formula (1), are obtained
During strong rammer saturated sand foundation, it is believed that in tiny time section, solid particle skeleton and pore water pressure can be considered
Static conditions, the stress of solid particle skeleton is solved using quasi-static model, while assuming the direction x, the direction z in tiny time section
Pore water pressure it is identical, then establish the saturated sand infinitesimal body stress in the direction x, be shown below,
In formula, γ is saturated sand bulk density；σxFor the direction saturated sand micro unit x stress；k0For coefficient of static earth pressure；X is full
With sand thickness；B is the strong rammer acceleration peak swing on saturated sand foundation ground；ω is the saturated sand soil under the conditions of strong rammer
The circular frequency of base, ω=2 π/T, T are the period；pfFor pore water pressure；
Formula (6) are substituted into formula (5), abbreviation arranges to obtain formula (7),
It is indicated in the hydraulic gradient of the micro unit that saturated sand foundation depth is z location, x-axis micro unit surfaces externally and internally are as follows:
In formula, γwFor underground water bulk density；
Formula (8) are substituted into formula (7), are enabledCvxIt is abbreviation, whole for the horizontal direction saturated sand foundation coefficient of consolidation
Reason obtains the Second Order Nonhomogeneous partial differential equation of excess pore water pressure, is shown below,
Formula (9) are solved using the separation of variable, strong rammer is obtained and acts on lower saturated sand foundation pore water pressure force function, such as formula
(18) shown in,
In formula, c1x、c2x、c3x、βxFor partial differential equation coefficient to be asked；
If strong rammer causes elastic wave to continue t=t1Time can make saturated sand foundation the liquefaction phenomenon of z-depth occur, then z
The direction depth saturated sand foundation micro unit x pore water pressure dynamic balance, i.e.,
In formula, g is acceleration of gravity；
Work as t1→ ∞,
c3x=γ zg+ (1-k0)γzB sinωt (20)
When hammer ram not yet contacts saturated sand, i.e. when t=0, the saturated sand micro unit pore water pressure in the direction x is place hole
Water pressure original value, function are
At this point, at z-depth, x=0, pore water pressure zero, i.e.,
c1x=-γ zg (22)
At z-depth, x=l, there is densification shell in saturated sand foundation ground under the P wave effect of strong rammer, the hydrostatic hole on the outside of shell
Gap water pressure and its internal saturated sand micro unit pore water pressure dynamic balance, then c2xSolution be
Formula (20), (22), (24) are substituted into formula (18),
Z-depth, x=l are substituted into formula (28), arranged
For the outer surface of the compression shell of saturated sand, at z-depth, micro unit horizontal direction pore water pressure is pf=γ zg, then
It enablesAnd sin ω t=1, it substitutes into formula (27), obtains single tamping point horizontal direction effectively and influence distance and be
In formula, JxFor saturated sand foundation horizontal direction Dynamic response characteristic parameter；CvxFor saturated sand foundation horizontal direction consolidation
Coefficient；T is that strong rammer fluctuates the propagation time in ground；B is ground acceleration amplitude peak caused by strong rammer；G is gravity acceleration
Degree；X is that the saturated sand foundation horizontal direction that the vibration of single tamping point strong rammer generates effectively influences distance；
The saturated sand foundation horizontal direction that then strong rammer vibration generates effectively influences spacing X and is
When the material of hydraulic reclamation saturated sand foundation is relatively uniform, in formula (29), horizontal direction saturated sand foundation consolidation system
Number CvxIt is determined according to geotechnological consolidation test, horizontal direction Dynamic response characteristic parameter is chosen by vertical Dynamic response characteristic parameter, by force
It is true to ram the vibration pickup data that ground acceleration amplitude peak B caused by action time parameter t, strong rammer rams test laying according to examination
It is fixed, parameter progress Preliminary design is read according to the survey that has for closing on place, close geological conditions.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6475717A (en) * | 1987-09-14 | 1989-03-22 | Daisue Kensetsu Kk | Dynamic compaction work and device therefor |
| CN101016740A (en) * | 2007-03-05 | 2007-08-15 | 武亚军 | Multiple pressurizing fast consolidated compacting soft earth foundation treatment method |
| CN104047280A (en) * | 2014-06-14 | 2014-09-17 | 叶吉 | Soft foundation fast separating and punning method |
| CN104652411A (en) * | 2014-11-04 | 2015-05-27 | 郑鲁平 | Composite foundation treatment method based on reinforcement, pretreatment and dynamic compaction of sandy soil |
| CN109183777A (en) * | 2018-10-24 | 2019-01-11 | 中国水利水电第四工程局有限公司 | A kind of quincunx construction method for laying water injection hole of pond dam foundation water filling of regulating and storing |
-
2019
- 2019-07-17 CN CN201910644015.4A patent/CN110344388B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6475717A (en) * | 1987-09-14 | 1989-03-22 | Daisue Kensetsu Kk | Dynamic compaction work and device therefor |
| CN101016740A (en) * | 2007-03-05 | 2007-08-15 | 武亚军 | Multiple pressurizing fast consolidated compacting soft earth foundation treatment method |
| CN104047280A (en) * | 2014-06-14 | 2014-09-17 | 叶吉 | Soft foundation fast separating and punning method |
| CN104652411A (en) * | 2014-11-04 | 2015-05-27 | 郑鲁平 | Composite foundation treatment method based on reinforcement, pretreatment and dynamic compaction of sandy soil |
| CN109183777A (en) * | 2018-10-24 | 2019-01-11 | 中国水利水电第四工程局有限公司 | A kind of quincunx construction method for laying water injection hole of pond dam foundation water filling of regulating and storing |
Cited By (1)
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| CN111898277A (en) * | 2020-08-06 | 2020-11-06 | 长沙理工大学 | Method for determining tamping settlement and optimal tamping times in dynamic compaction process |
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