CN115288162A - Reinforcing method for soft soil foundation fill slope - Google Patents
Reinforcing method for soft soil foundation fill slope Download PDFInfo
- Publication number
- CN115288162A CN115288162A CN202210873772.0A CN202210873772A CN115288162A CN 115288162 A CN115288162 A CN 115288162A CN 202210873772 A CN202210873772 A CN 202210873772A CN 115288162 A CN115288162 A CN 115288162A
- Authority
- CN
- China
- Prior art keywords
- slope
- soil
- dynamic compaction
- pier
- foundation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002689 soil Substances 0.000 title claims abstract description 200
- 238000000034 method Methods 0.000 title claims abstract description 52
- 230000003014 reinforcing effect Effects 0.000 title claims abstract description 20
- 238000005056 compaction Methods 0.000 claims abstract description 174
- 238000010276 construction Methods 0.000 claims abstract description 67
- 239000002131 composite material Substances 0.000 claims abstract description 27
- 230000002787 reinforcement Effects 0.000 claims abstract description 26
- 239000004575 stone Substances 0.000 claims abstract description 22
- 230000008569 process Effects 0.000 claims abstract description 20
- 238000007596 consolidation process Methods 0.000 claims abstract description 7
- 238000012360 testing method Methods 0.000 claims description 59
- 239000010410 layer Substances 0.000 claims description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 27
- 239000011148 porous material Substances 0.000 claims description 25
- 238000004080 punching Methods 0.000 claims description 18
- 238000013461 design Methods 0.000 claims description 17
- 239000003337 fertilizer Substances 0.000 claims description 14
- 238000009331 sowing Methods 0.000 claims description 13
- 238000004364 calculation method Methods 0.000 claims description 12
- 238000012545 processing Methods 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 11
- 239000011435 rock Substances 0.000 claims description 11
- 239000000945 filler Substances 0.000 claims description 10
- 238000012544 monitoring process Methods 0.000 claims description 9
- 239000002344 surface layer Substances 0.000 claims description 9
- 244000025254 Cannabis sativa Species 0.000 claims description 8
- 238000005520 cutting process Methods 0.000 claims description 8
- 238000006073 displacement reaction Methods 0.000 claims description 6
- 238000012423 maintenance Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 238000010899 nucleation Methods 0.000 claims description 5
- 238000004062 sedimentation Methods 0.000 claims description 5
- 239000003516 soil conditioner Substances 0.000 claims description 5
- 241000196324 Embryophyta Species 0.000 claims description 3
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 230000005484 gravity Effects 0.000 claims description 3
- 230000009191 jumping Effects 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 claims description 3
- 239000004576 sand Substances 0.000 claims description 3
- 238000010008 shearing Methods 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 230000004083 survival effect Effects 0.000 claims description 3
- 230000004888 barrier function Effects 0.000 claims description 2
- 238000009826 distribution Methods 0.000 claims description 2
- 238000005553 drilling Methods 0.000 claims description 2
- 238000013507 mapping Methods 0.000 claims description 2
- 239000000618 nitrogen fertilizer Substances 0.000 claims description 2
- 239000002686 phosphate fertilizer Substances 0.000 claims description 2
- 230000000087 stabilizing effect Effects 0.000 claims description 2
- 230000035515 penetration Effects 0.000 claims 2
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims 1
- 229940072033 potash Drugs 0.000 claims 1
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Substances [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 claims 1
- 235000015320 potassium carbonate Nutrition 0.000 claims 1
- 230000008901 benefit Effects 0.000 abstract description 8
- 239000002699 waste material Substances 0.000 abstract description 4
- 238000003912 environmental pollution Methods 0.000 abstract description 3
- 238000009412 basement excavation Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 239000004927 clay Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000012876 topography Methods 0.000 description 3
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 230000004224 protection Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 210000003462 vein Anatomy 0.000 description 2
- 229910021532 Calcite Inorganic materials 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- 230000006750 UV protection Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000001568 sexual effect Effects 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000004642 transportation engineering Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/20—Securing of slopes or inclines
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/20—Securing of slopes or inclines
- E02D17/207—Securing of slopes or inclines with means incorporating sheet piles or piles
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q10/00—Administration; Management
- G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
- G06Q10/063—Operations research, analysis or management
- G06Q10/0639—Performance analysis of employees; Performance analysis of enterprise or organisation operations
- G06Q10/06393—Score-carding, benchmarking or key performance indicator [KPI] analysis
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/23—Dune restoration or creation; Cliff stabilisation
Landscapes
- Engineering & Computer Science (AREA)
- Business, Economics & Management (AREA)
- Human Resources & Organizations (AREA)
- Mining & Mineral Resources (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Paleontology (AREA)
- Structural Engineering (AREA)
- Civil Engineering (AREA)
- Development Economics (AREA)
- Educational Administration (AREA)
- Economics (AREA)
- Entrepreneurship & Innovation (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Strategic Management (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Game Theory and Decision Science (AREA)
- Tourism & Hospitality (AREA)
- Quality & Reliability (AREA)
- General Business, Economics & Management (AREA)
- Operations Research (AREA)
- Marketing (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention provides a method for reinforcing a soft soil foundation filling side slope. The reinforcing method firstly adopts an improved process to reinforce the dynamic compaction replacement pier of the soft soil foundation, replaces the soft soil of the foundation with the broken stones to form a broken stone replacement pile composite foundation so as to enhance the bearing capacity of the foundation, accelerates the drainage consolidation process of the soft soil layer, obviously improves the soft soil parameters, secondly carries out superfilling reinforcement on the broken stone soil of the slope body backfilled with the slope, cuts the slope in a grading way, and arranges planting soil on the surface soil of the foundation for greening the slope surface of the slope. The method has the advantages of low construction cost, small environmental pollution, full utilization of the ground gravel soil, waste recycle, and good economic and social benefits.
Description
Technical Field
The invention relates to the technical field of slope reinforcement, in particular to a method for reinforcing a soft soil foundation filling slope.
Background
In recent years, the country proposes a double-carbon target, many industrial enterprises improve new processes, the process gradually changes to green, a production base is moved from a city to a mountain area, the infrastructure of a newly-built factory is large in scale and large in area, a large amount of flat ground is needed to meet the land use requirement, and a large area of high-excavation low-filling areas exist in the field. In the excavation area, a large amount of loose gravel soil is generated in the process of leveling earthwork of a construction site, the soil body is not easy to compact, the excavation and transportation engineering quantity is large, and the construction period is long. In the filling area, because the deep soft soil is distributed in the valley area with lower topography, the filling area has high thixotropy and high rheological property, and is easy to deform under the action of load, and particularly, the filling area is easy to deform under the condition of long-time uninterrupted external force and gravity.
Therefore, there is a problem that the bearing capacity of the foundation is difficult to satisfy if the soft soil foundation is used for filling the slope and the ultrahigh filling load is large if reinforcement is not performed. The high fill side slope of the gravel soil formed in the field is not easy to support, loose in soil quality and not easy to compact, and the retaining structure is easily adversely affected in the compaction construction process.
The traditional treatment method is that cast-in-situ bored piles are used as the anti-slide piles, the slope toe foundation needs to bear larger horizontal thrust, the pile bottom of the anti-slide pile is anchored in a hard rock-soil layer, and the engineering investment is huge. The cement soil mixing pile is adopted for construction, the treatment area is large, the engineering investment is large, and the treatment time is long. If the designed and reinforced side slope of the high fill of the gravelly soil to be formed is not designed and reinforced, a one-time backfilling mode is adopted, the side slope is easy to be unstable, and the safety of the road on the top of the slope and the construction and operation of industrial factory buildings are influenced. Therefore, the selection of an effective treatment scheme is particularly important, the soft soil foundation is reasonably treated, and meanwhile, the problems of piling and outward transportation of the gravel soil in the excavation area in the field and slope greening are solved, so that the method is particularly important. The invention is provided to solve the series of problems.
Disclosure of Invention
The invention aims to provide a method for reinforcing a soft soil foundation filling side slope, which aims to solve the problems of high construction cost, high reinforcing treatment difficulty, low drainage consolidation speed, and piling and outward transportation of gravelly soil in an excavation area in a field of the soft soil foundation filling side slope supporting construction, reduce the treatment cost, avoid secondary pollution, and simultaneously use the surface soil of the foundation for configuring slope greening planting soil to avoid outward transportation of soil resources.
In order to achieve the technical purpose, the invention provides a soft soil foundation fill slope reinforcement method which is characterized by comprising the following specific steps:
(1) Obtaining physical and mechanical property indexes of a soft soil slope soil layer according to geological survey, calculating the stability safety coefficient of the untreated soft soil slope according to a simplified Bischo method, determining a sliding arc coverage area which cannot meet the stability safety coefficient of the slope, and determining the depth and plane processing range of a soft soil reinforcing area; slope stability safety factor F s The calculation formula of (a) is as follows:
in the formula: f s -soft soil slope stability safety factor;
m θi -calculating coefficients;
l i length of the sliding arc at the bottom of the ith soil strip
G i -gravity of the ith soil strip, in units: kN;
G bi -ith earth bar vertical direction external force, unit: kN;
c i -cohesive force of foundation soil layer of ith soil strip, unit: kPa;
θ i -inclination of the i-th soil strip bottom slip plane;
(2) And (3) performing a slope gravel filling dynamic compaction test: representative of the soft soil consolidation zone determined in step (1)Performing a dynamic compaction test on the slope gravel filling in a sexual field, wherein the area of a test area is not less than 20mx20m, and performing a dynamic sounding test on a compaction test area when the compaction in the test area meets the sedimentation requirement to obtain the shear strength index c of the gravel filling dynamic compaction test area g 、
(3) And (3) dynamic compaction pier replacement test: before construction, performing a pile forming test in the soft soil reinforcing area determined in the step (1), determining the construction process and parameters of the dynamic compaction replacement pier, wherein the number of test piles is not less than 2, the pile diameter of the dynamic compaction replacement pier is 0.5-1.2 m, the pile depth is at least 1-2 m when penetrating through a sliding arc surface, and the pile depth is not more than 20m, and when the tamping of the test piles meets the settlement requirement, performing a dynamic sounding test on the test piles of the dynamic compaction replacement pier to obtain the shear strength index c of the test piles of the dynamic compaction replacement pier p And
(4) Setting the replacement rate m of the dynamic compaction replacement pier x And m is x The value range is as follows: 5% -30%; and m to be set x Value, shear strength index c of the dynamic compaction replacement pier determined according to the test determined in the step (2) p And
and determining the shear strength index c of the soil between the piles in the treatment area of the dynamic compaction replacement pier in geological exploration s And
the following formula is substituted to calculate the shearing strength index c of the composite foundation in the dynamic compaction replacement pier processing area sp And
c sp ＝m x c p +(1-m x )c s ③
in the formula: c. C p And the dynamic compaction replacement pier cohesive force is expressed by unit: kPa;
c s the cohesive force of the soil between the piles in the dynamic compaction replacement pier processing area is expressed by unit: kPa;
c sp -composite foundation cohesion force, unit: kPa;
m x setting the replacement rate of the dynamic compaction replacement pier;
(5) The shear strength index c of the composite foundation calculated in the step (4) is measured sp And
and (3) carrying out checking calculation on the stability safety coefficient of the composite foundation in the formulas (1) and (2) in the step (1), and setting the replacement rate m of the dynamic compaction replacement pier when the stability safety coefficient of the composite foundation meets the stability safety coefficient of the side slope x The value is the replacement rate m of the strong ramming replacement pier in the composite foundation;
(6) Calculating the interval s of the dynamic compaction replacement piers according to different pile arrangement modes according to the replacement rate m of the dynamic compaction replacement piers calculated in the step (5) and the pile diameter d obtained by pile testing in the step (2), and drawing a construction design drawing of the dynamic compaction replacement piers according to the calculation result;
when square piles are arranged: by
To obtain
When the piles are distributed in a regular triangle shape: by
To obtain
(7) Leveling a field, embedding a pore water pressure meter near a soft soil foundation reinforcing area outside a toe, and measuring a pore water pressure reference value of the foundation before the dynamic compaction replacement pier is constructed;
(8) Constructing dynamic compaction replacement piers according to the dynamic compaction replacement pier construction design drawing in the step (6) for the soft soil foundation reinforcement area outside the toe of the slope, constructing the dynamic compaction replacement piers at intervals, constructing from the inside of the slope to the outside of the slope, and extruding the soft soil out of the reinforcement area range outside the slope; the construction adopts a punching and expanding hammer and a column hammer, wherein the impact end of the punching and expanding hammer is set to be conical, and the column hammer is a cylindrical impact hammer; after the construction machine is in place, firstly, a punching hammer is adopted to tamp for multiple times at a construction point position to form a hole with the diameter matched with that of the hammer body, the depth is the designed depth of the dynamic compaction replacement pier, then, a dynamic compaction replacement pier column hammer is replaced, gravels are filled in the hole in a layered mode, and the gravels filled in the hole are tamped by the column hammer after each filling until the gravels filled in the hole reach a construction working surface;
(9) Monitoring the pore water pressure through a pore water pressure meter embedded in advance, fully tamping the surface layer of the field once after the pore water pressure is dissipated, wherein the tamping energy is 1500-2000kN.m, and the soft soil foundation treatment outside the toe is completed;
(10) The slope design is multi-stage slope-setting according to a slope rate method, the width of a graded street is controlled to be not less than 2m, the slope to be backfilled is subjected to layered treatment according to the designed height of the slope, the thickness of each layer of crushed rock to be treated is determined, and the crushed rock filling dynamic compaction construction is carried out on the slope according to the parameters of the crushed rock filling dynamic compaction test of the slope body in the step (3);
(11) And after the construction of the broken stone soil filling and dynamic compaction of the slope surface is finished, slope cutting and slope greening are carried out on the backfilled slope surface, and a slope drainage system is constructed.
The further technical scheme of the invention is as follows: in the step (1), the stability safety coefficient of the untreated soft soil slope is calculated through slope processing software, and the sliding arc coverage area which cannot meet the safety coefficient is analyzed by checking the passing position of the worst sliding surface, so that the depth and the plane processing range of the soft soil reinforcing area are determined; the slope processing software comprises Slide software, positive rock-soil processing software or Nanjing coulomb software; obtaining the size of the end face of the side slope and the stratum distribution through geological mapping and exploration to obtain the physical indexes and the mechanical indexes of each soil layer, inputting the exploration parameters into side slope processing software, establishing a two-dimensional side slope model, automatically searching the sliding arcs through the software, dividing the side slopes above the sliding arcs into strips, and directly obtaining the length l of the sliding arc at the bottom of the ith soil strip of the side slope i Gravity G of the i-th soil strip i I vertical external force G of the i-th soil strip bi I the cohesive force c of the foundation soil layer of the i-th soil strip i Inclination angle theta of bottom slip surface of ith soil strip i And calculating the slope stability coefficient through formulas (1) and (2).
The invention has the following excellent technical scheme: and (3) determining the treatment depth reaching the dynamic compaction replacement pier, the required hammer mass, hammer length and drop distance in the dynamic compaction replacement pier test in the step (2), and determining the layered filling amount and the tamping times through a process test.
The invention has the following excellent technical scheme: and (3) in the slope broken stone filling and dynamic compaction test in the step (3), parameters such as dynamic compaction energy, compaction point distance, compaction times, effective consolidation depth and the like are determined by combining trial compaction according to the following table, and corresponding single-click compaction energy is selected:
the invention has the following excellent technical scheme: calculating the amount of ploughing and planting soil required for covering the leveling side slope before leveling the field in the step (7), and correspondingly excavating and removing the land surface ploughing and planting soil during construction; and after the field is leveled, removing the barrier, paying off, positioning a control axis, piling a side line of the field, marking, and backfilling loose gravel soil on the original ground to form a hard shell layer on the surface layer of the field, so that mechanical equipment can conveniently enter the field for construction.
The invention has the following excellent technical scheme: in the step (8), in the process of multiple tamping at the construction point, when hole collapse occurs in the hole forming process of the impact expanding hammer, the hammer can be lifted to repeatedly impact to the designed depth, and finally a hole with the diameter matched with the diameter of the hammer body is formed; dividing the spaced pile positions into two groups by the dynamic compaction replacement piers for construction, measuring the pore water pressure value of the site by using a pore water pressure meter embedded in advance after the construction of the first group is completed, and constructing the second group of jumping positions from the beginning after the pore water pressure is dissipated; when the punching and expanding hammer is constructed, the punching and expanding hammer is raised to a certain height and then freely falls down to impact and form a hole, and the hole is tamped for multiple times, so that a hole with the diameter equal to that of the hammer body is formed on the ground, and the depth of the formed hole is 12-13 m; the average compaction coefficient of the filler in the dynamic compaction replacement pier pile body is not less than 0.98, the filler is filled along with the dynamic compaction, the accumulated tamping settlement of the tamping times is 1.5 to 2.0 times of the designed pier length, and the average tamping settlement of the last two times is not more than 250mm; and (3) adopting loose gravelly soil generated in the construction site earthwork leveling process for the dynamic compaction replacement pier filling in the step (8) and the filling material of the square slope body in the step (10), carrying out secondary crushing on gravels with larger particles, wherein the content of the particles with the particle size of more than 300mm is not more than 30%.
The invention has the advantages that: in the slope backfilling in the step (10), when the first-stage slope is backfilled, filling gravels in a range of 5m outside the top line of the slope of the soil-filled slope, so that the whole slope body can be reinforced by dynamic compaction; marking the position of the tamping point for the first time, measuring the elevation of the field, completing the tamping of all tamping points for the first time, filling the tamping pit with a bulldozer, and measuring the elevation of the field; after the specified interval time, completing all tamping passes according to the steps, and finally adopting low-energy full tamping; after each tamping is finished, detecting, and after the requirements are met, sequentially finishing the filling and dynamic tamping of a second-level slope, a third-level slope and the like upwards according to the steps to reinforce the whole slope body; and when the dynamic compaction surface reaches the designed elevation of the slope top by 40-60 cm, laying two layers of geogrids at intervals, after each layer of geogrid is laid, laying a medium sand cushion layer on the surface of each layer of geogrid, then laying uniform gravel soil, and carrying out layered rolling.
The invention has the following excellent technical scheme: in the step (11), the slope cutting is performed in a layering mode from top to bottom, the slope surface is manually trimmed by a bulldozer, and after the slope cutting is completed, the slope surface of the slope is greened; the slope greening specifically comprises the steps of digging surface soil to cover the slope, wherein the covering thickness is 20-25 cm, watering to wet the slope, then paving a three-dimensional net along the slope from top to bottom, fixing the slope from top to bottom by using U-shaped nails and steel nails to enable a net pad to be attached to the slope, and fixing the slope top and the slope foot according to design requirements respectively; after the three-dimensional net is completely paved and fixed, the surface soil and fertilizer are broadcast from the top of the slope to the bottom of the slope, and the soil is preferably coated by the thickness of the broadcast soil; applying base fertilizer and soil conditioner before sowing, broadcasting grass and irrigating seeds in sections, checking whether missed sowing exists or not at any time, watering in time after sowing, covering with geomembrane and watering for maintenance in time until the grass is planted into a lawn, wherein the survival rate is not less than 90%, and performing normal maintenance after the lawn is formed; the side slope drainage system is combined with a plant side slope drainage system; and finally, monitoring the slope engineering, and monitoring the horizontal displacement and the vertical displacement of the slope top and the deformation of the slope surface of the slope.
The invention has the advantages that: the dynamic compaction replacement pier and the equipment used for dynamic compaction in the step (2), the step (3), the step (8), the step (9) and the step (10) are the same equipment and consist of a crane, a cable and a detacher, and when the dynamic compaction replacement pier is constructed for pre-drilling, the detacher is connected with a punching and expanding hammer; when the dynamic compaction is constructed to replace the filler in the pier hole, the detacher is connected with the column hammer; when the slope is dynamically compacted, the detacher is connected with the rammer; and setting a dynamic compaction portal frame on the basis of a dynamic compactor when constructing the dynamic compaction replacement pier, and stabilizing the crane.
The invention has the following excellent technical scheme: applying a base fertilizer and a soil conditioner before sowing during slope greening, wherein the base fertilizer mainly comprises a nitrogen fertilizer, a phosphate fertilizer and a potassium fertilizer, and the ratio of the base fertilizer to the potassium fertilizer is 15 2 Left and right application.
The invention relates to a dynamic compaction replacement pier, which is characterized in that the treatment depth of the dynamic compaction replacement pier in the prior art is generally not more than 10m, in order to achieve greater depth, the invention adopts an improved process, firstly, a punching and expanding hammer is used for forming holes, the hammer head of the punching and expanding hammer is conical, the grounding pressure is high, the holes are easy to be punched, the hole forming depth in a soft soil stratum can reach 12-16 m, after the holes are formed, when the filling material is tamped, the rammed hammer is replaced, in order to prevent the conical hammer head from being damaged by tamping broken stones, the dynamic compaction replacement pier column hammer is cylindrical, the diameter of the ramming hammer is equal to the diameter of the punching and expanding hammer, and the broken stone filling material in the holes is tamped. If the depth of the soft soil layer to be treated exceeds 16m, earth surface covering soil layers can be dug and removed to form a shallow foundation pit, the dug and removed soil layers can be stacked aside and reserved as slope greening planting soil, broken stones with the thickness of 0.5-1.0 m are backfilled in the foundation pit to serve as a construction platform, a dynamic compaction replacement pier is constructed in the foundation pit, and after the construction is completed, the broken stones are backfilled in the foundation pit to meet the requirement that the depth treatment of the soft soil foundation is larger than 16 m.
The dynamic compaction replacement pier and the dynamic compaction equipment are the same equipment, the equipment is single and simple, the cost of construction equipment is low, the phenomenon of cross operation of various large-scale equipment is avoided, and construction can be carried out even in a narrow place. The tamping energy of the dynamic compaction replacement pier is suitable to be increased along with the depth of the tamping hole, the tamping energy is gradually increased from low energy level to high energy level, and a dynamic compaction portal frame can be set on the basis of a dynamic compactor to stabilize the crane in order to prevent the crane from overturning caused by high energy level dynamic compaction. The column hammer impact expanding method has large tamping energy and easy ground uplift, causes the loosening of the surface layer pile and the soil between the piles, thereby reducing the treatment effect, adopts the jump hole construction to reduce the pressure of the super-pore water in the soft soil of the foundation and fully removes the super-pore water in the soft soil. The invention carries out dynamic compaction treatment on the whole slope body in place, and the earth filling slope is superfilled with gravel soil within a certain range outside the slope top line, and the superfilling width is not less than 5m so as to meet the construction requirement of the dynamic compaction at the slope top line, so that the whole slope body can be reinforced, and the anti-skid property of the slope after slope cutting is enhanced. In the invention, two layers of three-dimensional geogrids are laid within the depth range of 50cm from the top of the slope, the creep property is required to be good, the ultraviolet resistance is required to be realized, the content of carbon black is required to be not less than 2%, in order to prevent the grids from being damaged by stone, the particle size of broken stone is required to be controlled to be less than 150mm, excavated mountain stone is required to be smashed, and the static pressure is realized by a smooth-wheel road roller within the depth range of 50cm from the top of the slope. The invention adopts a method of sowing grass and seeds in sections, namely, a method of sowing one section at a time is completed, so that the situations of uneven sowing or missed sowing caused by the fact that mechanical equipment with long side slopes cannot reach the sowing machine are avoided.
The invention has the beneficial effects that:
(1) The invention provides a method for calculating the reinforcement of a filling side slope of a soft soil foundation, which determines the depth and the plane processing range of a soft soil reinforcement area, the pile length and the interval of dynamic compaction replacement piers, the grading of a slope body, the reinforcement depth and other parameters, guides engineering practice through theoretical calculation results and plays an important role.
(2) The dynamic compaction replacement pier composite foundation is successfully applied to the treatment of the filling side slope of the soft soil foundation, and compared with an anti-slide pile and a cement mixing pile, the dynamic compaction replacement pier composite foundation has the advantages of being cheap in economy, controllable in technology, strong in operability, high in comprehensive economic benefit and the like; the dynamic compaction replacement pier can effectively improve the shear strength index of soft soil of the foundation, a large amount of crushed soil generated by excavating a mountain can be digested, engineering freight generated by outward transportation of waste slag is reduced, and the strength of the composite foundation formed by the dynamic compaction replacement pier and the soil between the piers can meet the design and specification requirements.
(3) The foundation part of the slope toe is composed of dynamic compaction replacement piers, because of the dynamic compaction replacement pier forming process, the gravel pile is moved outwards under the action of external load, the gravel extrudes the transverse soil body and has a vibration effect, the positions of soil body particles around the gravel pile are rearranged and tend to be compact, part of the gravel in the pile forming process also enters into the surrounding weak soil layer under the action of external force, the structure and the mechanical property of the soil body are changed, the load pressure is reduced by increasing the stress area, and after the pile body is formed, the gravel pile forms a good drainage structure, the shearing strength of the foundation can be improved, the removal of water in the weak soil is accelerated, the settlement consolidation time is shortened, and the foundation has certain waterproof and waterlogging-proof capabilities.
(4) The invention fully utilizes the gravel soil produced by field leveling to carry out dynamic compaction construction, the backfill thickness and the superfilling width of the gravel soil can be designed in a layered manner according to the dynamic compaction energy level, the compactness of the slope gravel soil is improved, and the integral stability of the slope can meet the design requirement.
(5) According to the invention, the gravel soil is superfilled in a certain range outside the slope surface line of the filled slope, so that the construction requirement of dynamic compaction at the top line of the slope can be met, and the technical problem that the gravel soil filled in the high-fill side slope of the gravel soil is not easy to compact in a certain range away from the top line of the slope is solved; the anti-skid performance of the cut slope can be enhanced, the construction is more convenient from top to bottom and the slope is cut in a layered and sectional manner by adopting a platform formed by excavating the super-filled gravelly soil, the construction difficulty of slope repairing is reduced, and the support construction safety of the high-fill side slope of the gravelly soil is ensured.
(6) The soft soil foundation filling side slope has high stability after being reinforced, solves the problems of piling and outward transportation of the gravel soil in the excavation area in the field, reduces the treatment cost, does not cause secondary pollution, and simultaneously uses the surface layer plowed soil of the foundation for preparing the planting soil to avoid outward transportation of a soil source; the reinforcement method reduces environmental pollution, changes waste resources into valuable substances, has high utilization rate, and has good economic and social benefits.
Drawings
FIG. 1 is a schematic diagram of the calculation of the sliding stability of the arc of the reinforced front slope in the present invention;
FIG. 2 is a plan view of the processing range of the dynamic compaction replacement pier in the embodiment;
FIG. 3 is a cross-sectional view of a dynamic compaction replacement pier treatment;
FIG. 4 is a schematic drawing of the punching and expanding hammer for punching and expanding holes in the dynamic compaction replacement pier in the embodiment;
FIG. 5 is a schematic diagram of the forced ramming of the replacement pier by the column hammer in the embodiment;
FIG. 6 is the cross-sectional view of the dynamic compaction of the slope body in the embodiment;
FIG. 7 is a schematic diagram of dynamic compaction of a slope body in the embodiment;
FIG. 8 is the completed construction of the filling slope of the soft soil foundation in the embodiment;
FIG. 9 is a schematic diagram of the calculation of the sliding stability of the arc of the reinforced slope in the embodiment;
in the figure: 1-crawler crane, 2-cable, 3-unhooking device, 4-impact expanding hammer, 5-column hammer, 6-dynamic compaction replacement pier, 7-slope surface line to be repaired, 8-dynamic compaction area, 9-overexcavation area, 10-original terrain line, 11-dynamic compaction replacement pier impact hole, 12-geogrid, 13-slope surface net hanging and grass planting structure, 14-packway drainage ditch,
Detailed Description
For further understanding of the contents, features and effects of the present invention, the present invention will be further described with reference to the accompanying drawings and examples. Fig. 1 to 6 are drawings of embodiments, which are drawn in a simplified manner and are only used for the purpose of clearly and concisely illustrating embodiments of the present invention. The following claims presented in the drawings are specific to embodiments of the invention and are not intended to limit the scope of the claimed invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Aiming at the problems in the prior art, the invention provides a safe construction method for earth and rockfill excavation filling and slope supporting engineering, and the invention is described in detail below with reference to the accompanying drawings.
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
As shown in fig. 4, 5, and 6, the marks 1 to 9 in the drawings are respectively: the device comprises a crawler crane 1, a mooring rope 2, a unhooking device 3, a punching and expanding hammer 4, a column hammer 5, a dynamic compaction replacement pier 6, a slope surface line 7 to be repaired, a dynamic compaction area 8 and an ultra-filling area 9. The construction process of the present invention will be further explained with reference to the embodiments with reference to the accompanying drawings.
In the embodiment, for a landform unit of a low-lying valley land of a certain construction field, the landform is complex, the north and the west of the land are higher, the east and the south of the land are lower, and the topography is more fluctuant. According to the design elevation, the field is leveled according to the principle of high digging and low filling. In the existing regions with lower topography at east and south sides, silt soft soil is distributed in a foundation soil layer, and the regions are leveled according to the designed elevation to form filling slopes. The field stratum can be divided into 3 engineering geological layers according to the characteristics of the field stratum. The engineering geological characteristics of the rock-soil layers from top to bottom are as follows:
layer (1): plain fill (Q) 4 ml ) Grey, off-white, slightly wet, loose, high compressibility, mainly powdery clay.
Layer (2): silty and silty clay (Q) 4 l ) The main part is grey and grey black, the soft plastic shape is the minor part. Contains organic matter, has light fishy smell, low dry strength, moderate toughness, slight luster and slight reaction after shaking.
Layer (3): powdery clay (Q) 4 al+pl ) Tan, yellow-brown. Soft plastic is mainly used, the part is plastic, the dry strength is high, the shaking reaction is avoided, the cutter section is slightly glossy, the cutter section is smooth and mainly comprises sticky grains and powder particles, and the layering characteristic is not obvious.
Layer (4): stroke fossil limestone (T1), biological structure, blocky structure, cryptocrystalline structure, and calcareous cementation. The rock mass is relatively complete and contains more calcite veins and quartz veins. The hardness degree of the rock is harder rock, and the basic quality grade of the rock is III.
Table 1 shows the design parameter table of rock-soil physical mechanical index of each soil layer
The concrete steps of the reinforcement treatment for the side slope are as follows:
(1) According to the physical and mechanical property indexes of main soil layers revealed by geological exploration, a simplified Bishou method is adopted, the unprocessed slope stability coefficient is calculated through slope software (Slide, rock soil and Culun of Nanjing),
slope stability safety factor F s The calculation formula of (c) is as follows:
in the formula: f s -soft soil slope stability safety factor;
m θi -calculating coefficients;
G i -gravity of the ith soil strip, in units: kN;
G bi -ith earth bar vertical direction external force, unit: kN;
c i -cohesive force of foundation soil layer of ith soil strip, unit: kPa;
θ i -inclination of the i-th soil strip bottom slide.
As shown in FIG. 1, the calculated safety factor is 1.097-less 1.35, and the requirement of the safety stability coefficient of the primary permanent slope is not met. Checking the passing position of the worst sliding surface, wherein the deepest position is about 10.5m below the ground surface, analyzing a sliding arc coverage area which cannot meet the safety coefficient, and determining the depth of a soft soil reinforcing area to be about 12m and the width of a plane processing range to be about 48m; a plan view of the treatment range of the dynamic compaction replacement pier 6 is shown in fig. 2.
(2) And (3) dynamic compaction test of the crushed stones on the slope: selecting a representative field on the slope of the soft soil reinforcing area determined in the step (1), performing a slope body broken stone filling dynamic compaction test, wherein the area of the test area is not less than 20mx20m, and performing a dynamic sounding test on the compaction test area when the compaction of the test area meets the sedimentation requirement to obtain the shear strength index c of the broken stone filling dynamic compaction test area g 、
(3) And (6) dynamic compaction replacement pier test: before construction, performing pile forming test in the soft soil reinforcing area determined in the step (1), determining the construction process and parameters of the dynamic compaction replacement pier, wherein the number of test piles is not less than 2, the pile diameter of the dynamic compaction replacement pier is 0.5-1.2 m, the treatment depth which can be reached by the dynamic compaction replacement pier 6 is determined to be about 12m, and when the tamping of the test pile meets the sedimentation requirement, the test pile passes throughObtaining the shear strength index c of the test pile of the test dynamic compaction replacement pier by a heavy dynamic detection test p ＝0kPa，
(4) Setting the replacement rate m of the dynamic compaction replacement pier x And m is x The value range is as follows: 5% -30%, preferably 10% -20%; and m to be set x Value, shear strength index c of the dynamic compaction replacement pier determined according to the test determined in the test of step (2) p And
and the shear strength index c of the soil between the piles within the depth range of the dynamic compaction replacement pier determined in the geological exploration s And
calculating the shear strength index c of the composite foundation after the dynamic compaction replacement pier and the broken stone filled dynamic compaction soil layer are combined by the following formula sp And
c sp ＝m x c p +(1-m x )c s ③
in the formula: c. C p And-dynamic compaction replacement pier cohesive force, unit: kPa;
c s the cohesive force of the soil between the piles within the depth range of the dynamic compaction replacement pier is expressed by unit: kPa;
c sp -composite foundation cohesion force, unit: kPa;
m x setting the replacement rate of the dynamic compaction replacement pier;
(5) The shear strength index c of the composite foundation calculated in the step (4) is measured sp And
substituting the stable safety coefficient of the composite foundation into the formulas (1) and (2) in the step (1) to calculate the stable safety coefficient of the composite foundation, and setting the replacement rate m of the dynamic compaction replacement pier when the stable safety coefficient of the composite foundation meets the stable safety coefficient of the side slope x The value is the replacement rate m of the dynamic compaction replacement pier in the composite foundation, namely m =0.20. The strength index values for which the ground meets the stability safety factor are thus obtained as shown in table 2:
table 2 shows the composite ground strength index c sp 、
Value of
When square piles are arranged, the pile is made of
To obtain
Assuming that the pile diameter d of the dynamic compaction replacement pier 6 is 1.2m, s =2.4m is obtained. The design pier is 12m long, the pier body material is hard coarse particle materials such as block stones, broken stones and the like with good gradation, and the content of particles with the particle size of more than 300mm is not more than 30%; and drawing according to the calculation resultAnd (5) outputting a construction design drawing of the dynamic compaction replacement pier.
(6) Before construction, the amount of soil for ploughing and planting required for covering and leveling the side slope is calculated, surface soil is correspondingly dug during construction, the field is leveled, and obstacles are removed.
(7) And paying off, determining a control axis, a piling field sideline and marking. Loose gravel soil is backfilled on the original ground, so that a hard shell layer is formed on the surface layer of the site, and mechanical equipment can conveniently enter the site for construction.
(8) And embedding a pore water pressure meter near the soft soil foundation consolidation area outside the toe of the slope, and measuring the pore water pressure reference value of the foundation before the dynamic compaction replacement pier 6 is constructed.
(9) As shown in fig. 4, the construction machine is in place, and the pile hammer is aligned with the pile position according to the diameter, the pile spacing, the pile length and the reinforcement plane range of the dynamic compaction replacement pier 6 calculated in the step (5). As shown in fig. 4, the impact end of the expanding hammer is set to be conical, and the expanding hammer is rammed on the ground for multiple times, so that a hole with a diameter approximately equal to that of the hammer body is formed on the ground. And then replacing a 6-column hammer of the dynamic compaction replacement pier, wherein the column hammer is a conical impact hammer, as shown in fig. 5, tamping the filler in the hole by using a hammer body, lifting the hammer body after tamping, continuously adding part of the filler into the hole, tamping the filler in the hole by using the hammer body, gradually increasing the point tamping energy from 800kN.m to 18000kN.m, filling along with tamping, wherein the single-point tamping frequency is not less than 10 times, specifically, the accumulated tamping frequency is determined by a field test, the accumulated tamping amount is 1.5-2.0 times of the designed pier length, and the average tamping amount of the last two times is not more than 250mm. Repeating the steps for a plurality of times until the filler reaches the construction operation surface.
(10) And (4) shifting the construction machine, repeating the steps to construct the next pile according to the construction from the inside of the slope to the outside of the slope in an interval construction mode, and extruding the soft soil out of the range of the reinforcement area outside the slope.
(11) Measuring the pore water pressure value of the field by using a pore water pressure meter which is embedded in advance, and constructing a dynamic compaction replacement pier 6 at the jumping position from the beginning after the pore water pressure is dissipated;
(12) And continuously monitoring the pore water pressure, fully compacting the surface layer of the field once after the pore water pressure is dissipated, fully compacting the pier top, wherein the compacting energy is 1500-2000kN.m, and finishing the soft soil foundation treatment.
(13) And (4) slope design is performed in a multistage slope release mode according to a slope ratio method, and the width of a graded pavement is 3m. As shown in fig. 6 and 7, the design height of the side slope is about 20m, the side slope to be backfilled is processed by 3 layers, the thickness of each layer of crushed soil to be processed is determined to be 7m, and the dynamic compaction depths of the upper layer and the lower layer are overlapped by 0.5-1.0 m; and backfilling the first-stage slope, wherein the slope height is 7m, and superfilling gravel soil in a certain range outside the slope top line of the soil-filled slope so as to meet the construction requirement of dynamic compaction at the slope top line. Marking the position of the tamping point for the first time, measuring the elevation of the field, and performing dynamic compaction and compaction with the compaction energy of 4000kN m for one time. Point ramming is carried out for 2 times, the distance between ramming points is 6.0m, the first time of point ramming is 4000kN.m, the second time of point ramming is 4000kN.m, and the number of times of point ramming and ramming is 6-8 times; tamping for 1 time, wherein the tamping energy is 2000kN.m,3 times, and the hammer diameter is overlapped for 1/4. The average ramming weight of the last two times of dynamic compaction is not more than 100mm. Filling the rammed pit with a bulldozer, and measuring the elevation of the field; after the specified interval time, completing all tamping passes according to the steps, and finally adopting low-energy full tamping.
(14) After the tamping is finished each time, the detection is carried out, after the requirements are met, the filling and dynamic tamping of a second grade slope, a third grade slope and the like are sequentially completed upwards according to the steps, and the whole slope body can be reinforced.
(15) And (3) when the dynamic compaction surface is 50cm higher than the designed elevation of the slope top, respectively paving a layer of geogrid at the depth of 25cm and 50cm, totaling 2 layers, paving a 50mm medium sand cushion layer on the surface of the geogrid after paving, paving uniform gravel soil, and carrying out layered rolling. So as to control the uneven settlement of the top of the slope.
(16) As shown in fig. 8, the slope is cut from the top to the bottom in layers, and the slope is trimmed manually by a bulldozer. Greening the slope surface of the side slope after slope cutting is finished, covering 20cm thick surface soil dug in the step (1) on the leveled slope surface, sprinkling water to wet, paving a three-dimensional net along the slope surface from top to bottom, and fixing the net pad to the slope surface from top to bottom by using U-shaped nails and steel nails; the top and the foot of the slope are respectively fixed according to the design requirements; after the three-dimensional net is completely paved and fixed, surface soil and fertilizer are manually broadcast from the top of the slope to the bottom of the slope, and the soil is preferably spread to cover the net. Applying base fertilizer and soil conditioner before seeding, manually sowing grass in sections to irrigate seeds, checking whether seeding is missed or not at any time, watering in time after seeding, covering with geomembrane and watering in time for maintenance until the grass is planted into a lawn, requiring the survival rate not less than 90%, and entering normal maintenance after the lawn is formed.
(17) And (3) building a drainage system of the side slope, and combining the drainage system with a plant area side slope drainage system.
(18) After the slope reinforcement is finished, performing arc sliding stability analysis on the slope, wherein a calculation diagram is shown in fig. 9, the worst sliding arc does not pass through a soft soil area reinforced by a dynamic compaction replacement pier 6, the overall stability of the slope is obviously improved, the minimum safety coefficient is 1.359>1.35, and the requirement of the safety stability of a first-level permanent slope is met; monitoring slope engineering, and monitoring horizontal displacement and vertical displacement of a slope top and slope surface deformation of the slope.
The soft soil foundation filling side slope has high stability after being reinforced, solves the problems of piling and outward transportation of the gravel soil in the excavation area in the field, reduces the treatment cost, does not cause secondary pollution, and simultaneously uses the surface layer plowed soil of the foundation for preparing the planting soil to avoid outward transportation of a soil source. The reinforcement method reduces environmental pollution, changes waste resources into valuable substances, has high utilization rate, and has good economic and social benefits.
In summary, the disclosure of the present invention is not limited to the above-mentioned embodiments, and persons skilled in the art can easily set forth other embodiments within the technical teaching of the present invention, but such embodiments are included in the scope of the present invention.
Claims (10)
1. A method for reinforcing a soft soil foundation fill side slope is characterized by comprising the following specific steps:
(1) Obtaining physical and mechanical property indexes of a soft soil slope soil layer according to geological survey, calculating the stability safety coefficient of the untreated soft soil slope according to a simplified Bischo method, determining a sliding arc coverage area which cannot meet the stability safety coefficient of the slope, and determining the depth and the plane processing range of a soft soil reinforcing area; slope stability safety factor F s The calculation formula of (c) is as follows:
in the formula: f s -soft soil slope stability safety factor;
m θi -calculating coefficients;
l i length of the sliding arc at the bottom of the ith soil strip
G i -gravity of the ith soil strip, in units: kN;
G bi -vertical force of ith soil stripe, unit: kN;
c i -cohesion of foundation soil layer of the ith soil strip, unit: kPa;
θ i -inclination of the i-th soil strip bottom slip plane;
(2) And (3) performing a slope gravel filling dynamic compaction test: selecting a representative field in the soft soil reinforcing area determined in the step (1), performing a slope broken stone filling dynamic compaction test, wherein the area of the test area is not less than 20mx20m, and performing a dynamic penetration test on the test compaction area when the test area is compacted and filled to meet the sedimentation requirement to obtain the shear strength index c of the broken stone filling dynamic compaction test area g 、
(3) Dynamic compaction replacement pier test: before construction, pile forming tests are carried out in the soft soil reinforcing area determined in the step (1), the construction process and parameters of the dynamic compaction replacement pier are determined, the number of the test piles is not less than 2, the pile diameter of the dynamic compaction replacement pier is 0.5-1.2 m, and the pile depth is that the pile penetrates through a sliding arc surfaceAt least 1-2 m, the pile depth is not more than 20m, when the tamping of the test pile meets the sedimentation requirement, the dynamic penetration test is carried out on the dynamic tamping replacement pier test pile to obtain the shear strength index c of the test dynamic tamping replacement pier test pile p And
(4) Setting the replacement rate m of the dynamic compaction replacement pier x And m is x The value range is as follows: 5% -30%; and m to be set x Value, shear strength index c of the dynamic compaction replacement pier determined according to the test determined in the step (2) p And
and determining the shear strength index c of the soil between the piles in the treatment area of the dynamic compaction replacement pier in geological exploration s And
the following formula is substituted to calculate the shearing strength index c of the composite foundation in the dynamic compaction replacement pier processing area sp And
c sp ＝m x c p +(1-m x )c s ③
in the formula: c. C p And the dynamic compaction replacement pier cohesive force is expressed by unit: kPa;
c s the cohesive force of the soil between the piles in the dynamic compaction replacement pier processing area is expressed by unit: kPa;
c sp -composite foundation cohesion force, unit: kPa;
m x setting the replacement rate of the dynamic compaction replacement pier;
(5) The shear strength index c of the composite foundation calculated in the step (4) is calculated sp And
and (3) carrying out checking calculation on the stability safety coefficient of the composite foundation in the formulas (1) and (2) in the step (1), and setting the replacement rate m of the dynamic compaction replacement pier when the stability safety coefficient of the composite foundation meets the stability safety coefficient of the side slope x The value is the replacement rate m of the dynamic compaction replacement pier in the composite foundation;
(6) Calculating the interval s of the dynamic compaction replacement piers according to different pile arrangement modes according to the replacement rate m of the dynamic compaction replacement piers calculated in the step (5) and the pile diameter d obtained by pile testing in the step (2), and drawing a construction design drawing of the dynamic compaction replacement piers according to the calculation result;
when square piles are arranged: by
To obtain
When the piles are distributed in the regular triangle shape: by
To obtain
(7) Leveling a field, embedding a pore water pressure meter near a soft soil foundation reinforcing area outside a toe of a slope, and measuring a pore water pressure reference value of the foundation before the construction of a dynamic compaction replacement pier;
(8) Constructing dynamic compaction replacement piers according to the dynamic compaction replacement pier construction design drawing in the step (6) for the soft soil foundation reinforcement area outside the toe of the slope, constructing the dynamic compaction replacement piers at intervals, constructing from the inside of the slope to the outside of the slope, and extruding the soft soil out of the reinforcement area range outside the slope; the construction adopts a punching and expanding hammer and a column hammer, wherein the impact end of the punching and expanding hammer is arranged to be conical, and the column hammer is a cylindrical impact hammer; after the construction machine is in place, firstly, a punching hammer is adopted to tamp for multiple times at a construction point position to form a hole with the diameter matched with that of the hammer body, the depth is the designed depth of the dynamic compaction replacement pier, then, a dynamic compaction replacement pier column hammer is replaced, gravels are filled in the hole in a layered mode, and the gravels filled in the hole are tamped by the column hammer after each filling until the gravels filled in the hole reach a construction working surface;
(9) Monitoring the pore water pressure through a pore water pressure meter embedded in advance, fully tamping the surface layer of the field once after the pore water pressure is dissipated, wherein the tamping energy is 1500-2000kN.m, and the soft soil foundation treatment outside the toe is completed;
(10) The slope design is multi-stage slope-setting according to a slope rate method, the width of a graded street is controlled to be not less than 2m, the slope to be backfilled is subjected to layered treatment according to the designed height of the slope, the thickness of each layer of crushed rock to be treated is determined, and the crushed rock filling dynamic compaction construction is carried out on the slope according to the parameters of the crushed rock filling dynamic compaction test of the slope body in the step (3);
(11) And after the construction of the broken stone soil filling and dynamic compaction of the slope surface is finished, slope cutting and slope greening are carried out on the backfilled slope surface, and a slope drainage system is constructed.
2. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: in the step (1), the stability safety coefficient of the unprocessed soft soil slope is calculated through slope processing software, and the worst slide surface is checkedThrough the position, analyzing a sliding arc coverage area which cannot meet the safety coefficient, and determining the depth and the plane processing range of a soft soil reinforcing area; the slope processing software comprises Slide software, positive rock-soil processing software or Nanjing coulomb software; obtaining the size of the end face of the side slope and the stratum distribution through geological mapping and reconnaissance to obtain the physical index and the mechanical index of each soil layer, inputting the reconnaissance parameters into side slope processing software, establishing a side slope two-dimensional model, automatically searching sliding arcs through the software, dividing the side slope above the sliding arcs into strips, and directly obtaining the length l of the sliding arc at the bottom of the ith soil strip of the side slope i Gravity G of the i-th soil strip i Vertical external force G of ith soil strip bi I the cohesive force c of the foundation soil layer of the ith soil strip i Inclination angle theta of bottom slip surface of ith soil strip i And calculating the slope stability coefficient through formulas (1) and (2).
3. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: and (3) determining the treatment depth reaching the dynamic compaction replacement pier, the required hammer mass, hammer length and drop distance in the dynamic compaction replacement pier test in the step (2), and determining the layered filling amount and the tamping times through a process test.
4. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: and (3) in the slope broken stone filling and dynamic compaction test in the step (3), parameters such as dynamic compaction energy, compaction point distance, compaction times, effective consolidation depth and the like are determined by combining trial compaction according to the following table, and corresponding single-click compaction energy is selected:
5. a soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: calculating the amount of ploughing and planting soil required for covering the leveling side slope before leveling the field in the step (7), and correspondingly excavating and removing the land surface ploughing and planting soil during construction; and after the field is leveled, removing the barrier, paying off, positioning a control axis, piling a side line of the field, marking, and backfilling loose gravel soil on the original ground to form a hard shell layer on the surface layer of the field, so that mechanical equipment can conveniently enter the field for construction.
6. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: in the step (8), in the process of multiple tamping at the construction point, when hole collapse occurs in the hole forming process of the impact expanding hammer, the hammer can be lifted to repeatedly impact to the designed depth, and finally a hole with the diameter matched with the diameter of the hammer body is formed; dividing the spaced pile positions into two groups by the dynamic compaction replacement pier for construction, measuring the pore water pressure value of the site by using a pore water pressure meter embedded in advance after the first group is constructed, and constructing the second group of jumping positions from the beginning after the pore water pressure is dissipated; when the punching and expanding hammer is constructed, the punching and expanding hammer is raised to a certain height and then freely falls down to impact and form a hole, and the hole is tamped for multiple times, so that a hole with the diameter equal to that of the hammer body is formed on the ground, and the depth of the formed hole is 12-13 m; the average compaction coefficient of the filler in the dynamic compaction replacement pier pile body is not less than 0.98, the filler is filled along with the dynamic compaction, the accumulated ramming amount of the ramming times is 1.5 to 2.0 times of the designed pier length, and the final two-stroke average ramming amount is not more than 250mm; and (3) adopting loose gravelly soil generated in the construction site earthwork leveling process for the dynamic compaction replacement pier filling in the step (8) and the filling material of the square slope body in the step (10), carrying out secondary crushing on gravels with larger particles, wherein the content of the particles with the particle size of more than 300mm is not more than 30%.
7. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: in the slope backfilling of the step (10), when the first-stage slope is backfilled, the gravel soil is superfilled within 5m of the top line of the filled slope, so that the whole slope body can be reinforced by dynamic compaction; marking the position of the tamping point for the first time, measuring the elevation of the field, completing the tamping of all the tamping points for the first time, filling a tamping pit by using a bulldozer, and measuring the elevation of the field; after the specified interval time, completing all tamping passes according to the steps, and finally adopting low-energy full tamping; after each tamping is finished, detecting, and after the requirements are met, sequentially finishing the filling and dynamic tamping of a second-level slope, a third-level slope and the like upwards according to the steps to reinforce the whole slope body; and when the dynamic compaction surface reaches the designed elevation of the slope top by 40-60 cm, laying two layers of geogrids at intervals, after each layer of geogrid is laid, laying a medium sand cushion layer on the surface of each layer of geogrid, then laying uniform gravel soil, and carrying out layered rolling.
8. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: in the step (11), the slope cutting is performed in a layering mode from top to bottom, the slope surface is manually trimmed by a bulldozer, and after the slope cutting is completed, the slope surface of the slope is greened; the slope greening specifically comprises the steps of digging soil on the surface of the land to cover the slope, wherein the covering thickness is 20-25 cm, watering to wet the slope, then paving a three-dimensional net along the slope from top to bottom, fixing the three-dimensional net from top to bottom by U-shaped nails and steel nails to enable the net to be attached to the slope, and fixing the top of the slope and the feet of the slope according to the design requirements; after the three-dimensional net is completely paved and fixed, the surface soil and fertilizer are broadcast from the top of the slope to the bottom of the slope, and the soil is preferably coated by the thickness of the broadcast soil; applying base fertilizer and soil conditioner before sowing, sowing grass in sections to irrigate seeds, checking whether seeding is missed or not at any time, watering in time after sowing, covering with geomembrane and watering in time for maintenance until the grass is planted into a lawn, wherein the survival rate is not lower than 90%, and performing normal maintenance after the lawn is formed; the side slope drainage system is combined with a plant side slope drainage system; and finally, monitoring the slope engineering, and monitoring the horizontal displacement and the vertical displacement of the slope top and the deformation of the slope surface of the slope.
9. A soft soil foundation fill slope reinforcement method as claimed in claim 1, wherein: the dynamic compaction replacement pier and the equipment used for dynamic compaction in the step (2), the step (3), the step (8), the step (9) and the step (10) are the same equipment and consist of a crane, a cable and a detacher, and when the dynamic compaction replacement pier is constructed for pre-drilling, the detacher is connected with a punching and expanding hammer; when the dynamic compaction is constructed to replace the filler in the pier hole, the detacher is connected with the column hammer; when the slope is dynamically compacted, the detacher is connected with the rammer; and setting a dynamic compaction portal frame on the basis of a dynamic compactor when constructing the dynamic compaction replacement pier, and stabilizing the crane.
10. A soft soil foundation fill side slope reinforcement method of claim 8, characterized in that, when the side slope is afforested, base fertilizer and soil conditioner are applied before seeding, the base fertilizer mainly comprises nitrogen fertilizer, phosphate fertilizer and potash fertilizer, the ratio of 15 2 Left and right application.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210873772.0A CN115288162B (en) | 2022-07-25 | 2022-07-25 | Reinforcing method for soft soil foundation filling side slope |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210873772.0A CN115288162B (en) | 2022-07-25 | 2022-07-25 | Reinforcing method for soft soil foundation filling side slope |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115288162A true CN115288162A (en) | 2022-11-04 |
| CN115288162B CN115288162B (en) | 2023-09-22 |
Family
ID=83823887
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210873772.0A Active CN115288162B (en) | 2022-07-25 | 2022-07-25 | Reinforcing method for soft soil foundation filling side slope |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115288162B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116556264A (en) * | 2023-06-06 | 2023-08-08 | 中国水利水电科学研究院 | Slope reinforcement method combining vertical drainage body with drainage |
| CN117027013A (en) * | 2023-08-08 | 2023-11-10 | 福建省地质工程勘察院 | Filling slope reinforced by microorganism deposited calcium carbonate technology and construction method thereof |
| CN117803002A (en) * | 2023-11-08 | 2024-04-02 | 江苏纬信工程咨询有限公司 | Mountain high-steep slope structure construction method and system based on substrate filling |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10237856A (en) * | 1997-02-27 | 1998-09-08 | Shimizu Corp | Construction mehtod for soil improvement using both pile and sand compaction pile |
| CN109826174B (en) * | 2018-12-29 | 2021-03-30 | 合肥工业大学 | Method for determining range of deep region of slope reinforcement |
| CN110210175A (en) * | 2019-06-21 | 2019-09-06 | 贵州正业工程技术投资有限公司 | A kind of composite foundation embankment side slope finite element calculating method for stability |
| CN111241621B (en) * | 2020-01-13 | 2022-04-19 | 西南交通大学 | Stability evaluation method for high-strength pile composite foundation under embankment |
| JP6944164B1 (en) * | 2020-04-01 | 2021-10-06 | 国立大学法人茨城大学 | Ground improvement method and improved ground structure |
| CN112301953B (en) * | 2020-11-25 | 2021-12-31 | 廊坊中达水利工程有限公司 | Construction method for river course slope protection slope toe by cement soil mixing pile |
| CN112597569B (en) * | 2020-12-17 | 2023-05-16 | 贵州正业工程技术投资有限公司 | Composite foundation filling slope stability evaluation method based on simplified PicoPu method |
-
2022
- 2022-07-25 CN CN202210873772.0A patent/CN115288162B/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116556264A (en) * | 2023-06-06 | 2023-08-08 | 中国水利水电科学研究院 | Slope reinforcement method combining vertical drainage body with drainage |
| CN116556264B (en) * | 2023-06-06 | 2023-09-22 | 中国水利水电科学研究院 | Slope reinforcement method combining vertical drainage body with drainage |
| CN117027013A (en) * | 2023-08-08 | 2023-11-10 | 福建省地质工程勘察院 | Filling slope reinforced by microorganism deposited calcium carbonate technology and construction method thereof |
| CN117803002A (en) * | 2023-11-08 | 2024-04-02 | 江苏纬信工程咨询有限公司 | Mountain high-steep slope structure construction method and system based on substrate filling |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115288162B (en) | 2023-09-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115288162B (en) | Reinforcing method for soft soil foundation filling side slope | |
| CN113445396B (en) | High-fill road foundation filling construction method for high liquid limit soil road section | |
| CN103790166B (en) | Method for treating foundation of loess area saturated zone slope filling and digging joint part | |
| CN103806432B (en) | Method for treating foundations in slope filling and digging joint part of wet and soft zone in loess region | |
| CN104264680B (en) | The method for processing foundation of Tian Wa joint portion, a kind of collapsible loess slope | |
| CN108486976B (en) | Roadbed structure at mountain highway filling and digging junction and construction method thereof | |
| CN103510504B (en) | High saturated uneven reclaimed ground processing method | |
| CN103074882A (en) | Construction method for reinforcing island-type perennial frozen-soil foundation by adopting gravel piles | |
| CN110777588A (en) | Pressure filling construction method for soil-stone mixed high-filling roadbed | |
| CN107119520A (en) | The soft base combined type of coastal tidal, which is changed, fills out structure and Treatment Methods | |
| CN107859041B (en) | The construction method of collapsible loess zanjon high roadbed structure | |
| CN108978385A (en) | A kind of roadbed construction method on the road Tong Cun | |
| CN116377780A (en) | Mountain highway high-fill roadbed filling construction method | |
| CN104695419A (en) | Soft soil roadbed construction method | |
| CN114215074A (en) | Ditch earthwork backfilling method | |
| CN206800092U (en) | The soft base combined type of coastal tidal, which is changed, fills out structure and Roadbed by offshore soft clay | |
| CN110029626B (en) | Reinforcing treatment method for revetment foundation on soft stratum slope | |
| CN206385525U (en) | A kind of timber structure for preventing the high backfill earthwork from sinking | |
| CN114541429B (en) | Multistage slope-pasting loess high-fill slope protection treatment system | |
| CN109056441A (en) | The soft soil roadbed three-dimensional reinforced structure of convolution and construction method are knitted in stake- | |
| CN218116492U (en) | Reinforcing treatment structure for soft soil foundation fill side slope | |
| CN106337409A (en) | Method for treating peat soil foundation through preloading in combination with salt piles | |
| RU2273687C1 (en) | Roadbed and roadbed forming method | |
| CN110080266A (en) | Method for improving bearing capacity of pile foundation under construction by replacing and filling soil between piles | |
| CN114016493B (en) | Soft foundation reclamation construction method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 430080 No. 17 metallurgical Avenue, Qingshan District, Hubei, Wuhan Patentee after: MCC Wukan Engineering Technology Co.,Ltd. Address before: 430080 No. 17 metallurgical Avenue, Qingshan District, Hubei, Wuhan Patentee before: WUHAN SURVEYING GEOTECHNICAL RESEARCH INSTITUTE Co.,Ltd. OF MCC |