Pile foundation side soft soil foundation road friction resistance eliminating structure and construction method
Technical Field
The invention relates to the field of soft soil foundation road construction, in particular to a friction eliminating structure of a pile foundation side soft soil foundation road and a construction method.
Background
The house or the station site on the soft soil foundation usually adopts a pile foundation, the settlement amount is generally tiny, but the periphery of the house or the station site is close to a road to save cost, soft soil treatment measures are simpler, larger settlement difference often exists between the house or the station site and the periphery of the house or the station site, and the junction of the house or the station site and the periphery of the house or the station site is difficult to uniformly settle with the road surface close to the other end of the house or the station site due to the existence of frictional resistance between the road surface, a base layer and a soft soil treatment part and a pile foundation under the house or the station site, so that a concave inclined curve is formed, the use and the environment are influenced, and even the road surface structure is damaged.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide the friction eliminating structure and the construction method for the soft foundation road at the pile foundation side, which have the advantages of simple structure, convenient construction, low cost and reliable quality.
The technical problems of the invention are realized by the following technical scheme:
The utility model provides a pile foundation side soft soil foundation road eliminates friction structure and construction method, includes setting up many pile foundations that constitute the multirow in soft soil foundation under house or station yard, and this many pile foundation sides is the soft soil layer that is close to the road, soft soil layer on lay solidification soil layer, geogrid, basic unit and pavement layer in proper order, and solidification soil layer, geogrid, basic unit, pavement layer jointly with be equipped with the isolation layer between the many pile foundations that are close to, this isolation layer is for doing vertical extension setting along road length direction, reduce or eliminate solidification soil layer, basic unit, pavement layer jointly with the friction of many pile foundation sides that are close to makes the pavement layer subside along with soft soil layer and solidification soil layer evenly.
The total sedimentation of the solidified soil layer and the soft soil layer in the adjacent roadFor simplicity of calculation, post-construction settlement of pavement layers and substrates in adjacent roads is negligible, and the weights of pavement layers and substrates per unit length and the loads of vehicles as solidified soil layers and soft soil layers are/>; It is assumed that frictional resistance/>, which is generated on the side of the plurality of pile foundations adjacent to the solidified soil layer and the soft soil layer togetherThe pavement layer sedimentation curve under the action of (a) is/>According to the law of conservation of energy, load/>Potential energy loss and frictional resistance/>For total sedimentation/>The work is equal, the total sedimentation/>, of the solidified soil layer and the soft soil layer in the adjacent roadEquation of sedimentation curve/>And frictional resistance/>Calculated from the following formula:
Equation one,
Total sedimentation of solidified and soft soil layers
Formula II,
Equation of sedimentation curve
Formula III,
Frictional resistance generated by solidified soil layer and soft soil layer together and adjacent pile foundation sides
Equation four,
No isolating layer is arranged, namely, when the soil layer is solidified, the soft soil layer actually rubs againstAt the time, the sedimentation curve isActual frictional resistance/>The unsettled height of the solidified soil layer and the soft soil layer which are caused by the method and the adjacent pile foundation sides is equal to/>Requirements/>;
After the isolating layer is arranged, when the soil layer is solidified and the friction resistance is actually applied to the soft soil layerAt the time, the sedimentation curve isActual frictional resistance/>The unsettled height of the solidified soil layer and the soft soil layer which are caused by the method and the adjacent pile foundation sides is equal to/>Requirements/>;
It can be seen that the provision of the isolating layer can reduce until the actual frictional resistance is eliminatedI.e./>Or/>To make the actual friction resistanceThe induced non-settled height/>, of the solidified soil layer and the soft soil layer together with the adjacent pile foundation sidesOr/>Namely, subsidence of a plurality of rows of pile foundation sides adjacent to the road surface and uniform subsidence of the road surface at the other end under a house or a station;
The meaning of each symbol in the formula I, the formula II, the formula III and the formula IV is as follows:
-total sedimentation of solidified and soft soil layers, equal to the actual friction/> Solidifying soil layer and soft soil layer together with adjacent multi-pile foundation side non-settlement height,/>, and;
After the isolation layer is arranged, when the soil layer is solidified, the actual friction resistance of the soft soil layer/>Solidifying soil layer and soft soil layer together with adjacent multi-pile foundation side non-settlement height,/>, and;
-The allowed unsettled height of the solidified soil layer, soft soil layer together with the adjacent pile foundation sides,/>;
-And solidified soil layer and soft soil layer characteristics/>And/>A sedimentation transfer matrix of interest;
-hankel transformation parameters;
Thickness weight per unit length of pavement and substrate and vehicle load,/> ;
-Abscissa and ordinate of the origin coordinate system of the road surface at the other end adjacent to the house or yard,/>, respectively;
-Sedimentation curve coefficients of solidified and soft soil layers,/>;
Width of the road layer and the base layer,/>;
-Sum of thicknesses of solidified soil layer, base layer and road layer,/>;
-Friction stress of vertical surfaces of solidified soil layer, base layer and road layer,/>;
Young's modulus, poisson's ratio,/>, of the cured soil layerDimensionless;
young's modulus, poisson's ratio,/>, of soft soil layer And is dimensionless.
The isolation layer is formed by spraying hot asphalt and asphalt felt which are arranged between a plurality of pile foundation sides and adjacent solidified soil layers in a segmented mode along the length direction of the road, the sprayed hot asphalt is in smooth contact with the surface of the pile foundation, friction resistance is reduced, and 1-2 layers of asphalt felt are paved outside the sprayed hot asphalt;
The solidified soil layer is a dense soil body which is prepared by adding a curing agent into soft soil on site, uniformly stirring and then rolling.
The geogrid is a two-dimensional latticed geosynthetic material formed by thermoplastic or mould pressing of polypropylene and polyvinyl chloride of high polymer.
The base layer is paved by the materials of the dead slag or the mud and crushed stone.
The pavement layer is formed by paving an asphalt concrete surface layer or a block stone.
A construction method for eliminating friction structure of soft soil foundation road at pile foundation side comprises the following steps:
step one, calculating a solidified soil layer and a soft soil layer And/>
① Testing the compression strength of 7-day age and 28-day age of the curing agent proportion of different doping amounts, and preferably determining the doping proportion of the curing agent under the condition of meeting the design requirement;
② Testing to determine the characteristic parameters of solidified soil layer and soft soil layer 、/>;;
③ Testing friction stress between isolation layer and solidified soil layer and soft soil layerMeasures are taken to reduce friction stressA value;
④ The friction resistance of the solidified soil layer (3) and the soft soil layer (2) is calculated by a formula I, a formula III and a formula IV respectively AndMeets/>Requirements;
Step two, solidifying soft soil
① Removing the cultivated soil on the surface layer;
② Gradually excavating to the designed depth of the solidified soil layer by using an excavator in sections of 10-20 m, uniformly broadcasting the solidifying agent according to the mixing proportion of the solidifying agent, and uniformly stirring the soft soil and the solidifying agent by using an excavator bucket;
step three, installing an isolation layer
① Digging grooves with the width of 80 cm-100 cm and the depth to the bottom surface of the solidified soil layer by using an excavator along the length direction of the road surface in sections of 10 m-20 m between a plurality of pile foundation sides in a soft soil foundation under a house or a station yard and the adjacent solidified soil layer which is uniformly stirred;
② The soil layer among the pile foundations is compacted by an excavator bucket or manually, and exposed edge and corner concrete of the pile foundations is knocked down by a hammer or ground down by a grinding wheel;
③ Heating the pure asphalt to 80 0C~1000 ℃, and spraying hot asphalt from bottom to top by using an asphalt spray gun in sections to ensure that the hot asphalt is adhered to the soil surface between pile foundations, wherein the thickness is 1 cm-2 cm;
④ After the hot asphalt is cooled to normal temperature, 1-2 layers of asphalt felts are paved on the surface of the asphalt adhered to soil between the pile foundations and the pile foundations from bottom to top in a segmented way, the bottom 50 cm-80 cm of the asphalt felts are folded into a horizontal shape and paved on the top surface of soft soil to be pressed by solidified soil, the asphalt felts are tensioned upwards, and the asphalt felts are temporarily fixed on the pile foundations by cement nails at the top; extending a plurality of felts along the length direction of the road, wherein each felt is extended and overlapped by 5 cm-10 cm;
⑤ Paving and tensioning each section of isolation layer with the thickness of 10-20 m, and backfilling the excavated trench with solidified soil to be full;
Fourth, rolling solidified soil and curing
① After the solidified soil layer and the isolation layer are finished, the solidified soil layer needs to be preliminarily compacted by a light road roller and other machines within 1 d;
② In order to prevent the volatilization of water and the influence of rainwater in the curing process, paving 1 layer of plastic film on the surface of a cured soil layer for curing;
③ After 14d, leveling the surface layer of the solidified soil layer by using a light bulldozer or a man;
④ Testing and detecting the quality of the solidified soil layer, and meeting the design requirements;
Step five, paving geogrid
Spreading the geogrid on the surface of a solidified soil layer, reserving the length of 80 cm-100 cm of the edge of the pavement at two ends, and overlapping each geogrid with the length of 10 cm-20 cm;
Step six, filling the base layer
① Filling a first layer of slag or mud and crushed stone for 30 cm-50 cm, compacting by using a medium-sized road roller, wherein the compactness meets the design requirement;
② Folding the geogrid at the edge of the reserved pavement, placing the top surface of the first layer of the slag or the mud-formed broken stone, continuously filling the second layer of the slag or the mud-formed broken stone for 30 cm-50 cm, and compacting by using a medium-or large-sized road roller until the slag or the mud-formed broken stone is filled and compacted to the design thickness, wherein the compactness meets the design requirement;
Step seven, paving the pavement
① Pulling out cement nails temporarily fixed on a plurality of pile foundations at the top of the felt;
② Paving an asphalt concrete pavement layer or a paved stone pavement.
Compared with the prior art, the invention mainly designs a friction eliminating structure of a soft foundation road at the pile foundation side, which is formed by a plurality of piles and solidified soil layers, geogrids, base layers and pavement layers which are arranged in the soft foundation at a house or a station and are adjacent to the road at the pile foundation side.
Drawings
Fig. 1 is a schematic view of an elevation of the structure of the present invention.
FIG. 2 is a plot of sedimentation and force calculations.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the drawings.
1-2, 1, Pile foundation, 2, soft soil layer, 3, solidified soil layer, 4, geogrid, 5, base layer, 6, road surface layer and 7, isolation layer.
The utility model provides a pile foundation side soft soil foundation road eliminates friction structure and construction method, as shown in fig. 1, belong to a soft soil foundation road construction field, including setting up the many pile foundations 1 that constitute the multirow in soft soil foundation under house or station yard, this many pile foundation side is the soft soil layer 2 that approaches the road, lay solidified soil layer 3, geogrid 4, basic unit 5 and pavement layer 6 on the soft soil layer in proper order, and be equipped with isolation layer 7 between solidified soil layer 3, geogrid 4, basic unit 5, pavement layer 6 jointly and the many pile foundations 1 that approach.
The solidified soil layer 3 is a novel environment-friendly road construction material, and is prepared by adding a curing agent into soft soil in situ to uniformly stir, so that the curing agent and the soft soil perform physical and chemical reactions, and the soft soil is rolled into a compact soil body after being solidified, so that the engineering performances of the soft soil such as compressive strength, water stability, freezing stability, compression reduction and the like can be improved, and the method is a relatively simple and economical soft soil foundation treatment measure.
The geogrid 4 is a main geosynthetic material, is a two-dimensional latticed material formed by thermoplastic or mould pressing of high molecular polymers such as polypropylene, polyvinyl chloride and the like, and has remarkable effects of enhancing shear resistance of soil body and reinforcing the soil body to improve the integrity and load force of the soil body.
The base layer 5 is paved by a slag or mud-bonded stone material, and has certain strength and stability; the pavement layer 6 is formed by paving an asphalt concrete surface layer or a block stone; the isolation layer 7 consists of 1-2 layers of felt and asphalt, and is vertically arranged between a plurality of pile foundations under a house or a station and adjacent pavement, foundation and solidified soil along the length direction of the pavement; therefore, friction between the solidified soil layer 3, the base layer 5 and the pavement layer 6 and the adjacent pile foundation sides can be reduced or eliminated through the isolation layer 7, and the solidified soil layer 3 and the soft soil layer 2 can be uniformly settled.
At the same time, the total sedimentation of the solidified soil layer 3 and the soft soil layer 2 in the adjacent roadFor simplicity of calculation, post-construction settlement of the pavement layer 6 and the foundation layer 5 in the adjacent road is negligible, and the weights of the pavement layer 6 and the foundation layer 5 per unit length and the loads of the vehicle as the solidified soil layer 3 and the soft soil layer 2 are/>; Let us say that frictional resistance/>, which is generated on the side of the plurality of pile foundations adjacent to the solidified soil layer 3 and the soft soil layer 2 togetherThe sedimentation curve of the pavement layer 6 under the action of (a) is/>According to the law of conservation of energy, load/>Potential energy loss and frictional resistance/>For total sedimentation/>The work is equal, the solidified soil layer 3 and the soft soil layer 2 in the adjacent road are settled/>Equation of sedimentation curve/>And frictional resistance/>Calculated from the following formula:
Equation one,
Total sedimentation of solidified soil layer 3 and soft soil layer 2
Formula II,
Equation of sedimentation curve
Formula III,
The solidified soil layer 3 and the soft soil layer 2 together generate frictional resistance with a plurality of adjacent pile foundation sides
Equation four,
No isolation layer 7 is provided, i.e. when the solidified soil layer 3 and the soft soil layer 2 actually have frictional resistanceAt the time, the sedimentation curve isActual frictional resistance/>The unsettled height of the solidified soil layer 3 and the soft soil layer 2 which are caused together and adjacent to the pile foundation sides is equal to/>Requirements/>;
After the isolating layer 7 is arranged, when the soil layer 3 is solidified and the soft soil layer 2 actually has frictional resistanceAt the time, the sedimentation curve isActual frictional resistance/>The unsettled height of the solidified soil layer 3 and the soft soil layer 2 which are caused together and adjacent to the pile foundation sides is equal to/>Requirements/>;
It can be seen that the provision of the barrier layer 7 reduces until the actual frictional resistance is eliminatedI.e./>Or/>To make the actual friction resistanceThe induced non-settled height/>, of the solidified soil layer and the soft soil layer together with the adjacent pile foundation sidesOr/>Namely, subsidence of a plurality of rows of pile foundation sides adjacent to the road surface and uniform subsidence of the road surface at the other end under a house or a station;
The meaning of each symbol in the formula I, the formula II, the formula III and the formula IV is as follows:
-total sedimentation of solidified soil layer 3 and soft soil layer 2, equal to when actual friction/> The non-settlement height of the solidified soil layer 3 and the soft soil layer 2 together with the adjacent pile foundation sides,/>The calculation formula and method of (c) are referred to a manual or literature for calculating sedimentation of a multi-layer horizontal layered foundation, such as "calculation analysis of total additional stress and sedimentation of horizontal layered foundation (Luo Shiyi: university of Chang's university, studies, 2003)" and can be determined by experiments,/>;
After the isolation layer 7 is arranged, when the soil layer 3 and the soft soil layer 2 are solidified, the actual friction resistance/>The non-settlement height of the solidified soil layer 3 and the soft soil layer 2 together with the adjacent pile foundation sides,/>;
-The allowed unsettled height of the solidified soil layer 3, soft soil layer 2 together with the adjacent pile foundation sides,/>;
Characteristics of solidified soil layer 3 and soft soil layer 2/>And/>Regarding the sedimentation transfer matrix, reference can be made to "analysis of total additional stress and sedimentation calculation of horizontal lamellar foundations (Luo Shiyi: university of Changan's Shu, 2003");
-Hankel (Hankel) transformation parameters;
Thickness weight per unit length of pavement layer 6 and substrate 5 and vehicle load,/> ;
-Abscissa and ordinate of the origin coordinate system of the road surface at the other end adjacent to the house or yard,/>, respectively;
-Sedimentation curve coefficients of solidified soil layer 3 and soft soil layer 2,/>;
Width of the pavement layer 6 and the base layer 5,/>;
-Sum of thicknesses of solidified soil layer 3, base layer 5 and road layer 6,/>;
Friction stress of vertical surfaces of solidified soil layer 3, base layer 5 and road layer 6,/>;
Young's modulus, poisson's ratio,/>, of the cured soil layer 3Dimensionless;
young's modulus, poisson's ratio,/>, of soft soil layer 2 And is dimensionless.
In addition, the construction method for eliminating friction structure of soft soil foundation road at pile foundation side mainly comprises the following steps:
step one, calculating a solidified soil layer and a soft soil layer And/>
① Testing the compression strength of 7-day age and 28-day age of the curing agent proportion of different doping amounts, and preferably determining the doping proportion of the curing agent under the condition of meeting the design requirement;
② Test to determine the characteristic parameters of the solidified soil layer 3 and the soft soil layer 2 、/>;
③ Test of friction stress between the isolation layer 7 and the solidified soil layer 3 and soft soil layer 2Measures are taken to reduce friction stress/>A value;
④ The friction resistance of the solidified soil layer 3 and the soft soil layer 2 is calculated according to the formula I, the formula III and the formula IV respectively And/>Meets/>Requirements;
Step two, solidifying soft soil
① The cultivated soil with the surface layer of about 30cm is removed;
② Gradually excavating to the designed depth of the solidified soil layer by using an excavator in sections of 10-20 m, uniformly broadcasting the solidifying agent according to the mixing proportion of the solidifying agent, and uniformly stirring the soft soil and the solidifying agent by using an excavator bucket;
step three, installing an isolation layer
① Digging grooves with the width of 80 cm-100 cm and the depth to the bottom surface of the solidified soil layer by using an excavator along the length direction of the road surface in sections of 10 m-20 m between a plurality of pile foundation sides in a soft soil foundation under a house or a station yard and the adjacent solidified soil layer which is uniformly stirred;
② The soil layer among the pile foundations 1 is clapped by an excavator bucket or manually, exposed corner concrete of the pile foundations is beaten by a hammer or ground by a grinding wheel;
③ Heating the pure asphalt to 80 0C~1000 ℃, and spraying hot asphalt from bottom to top by using an asphalt spray gun in sections to ensure that the hot asphalt is adhered to the soil surface between pile foundations 1 and 1 cm-2 cm thick;
④ After the hot asphalt is cooled to normal temperature, 1-2 layers of asphalt felts are paved on the surface of the asphalt adhered to soil between the pile foundations and the pile foundations from bottom to top in a segmented way, the bottom 50 cm-80 cm of the asphalt felts are folded into a horizontal shape and paved on the top surface of soft soil to be pressed by solidified soil, the asphalt felts are tensioned upwards, and the asphalt felts are temporarily fixed on the pile foundations 1 by cement nails at the top; multiple felts can be lengthened along the length direction of the road, and each felt is lengthened and overlapped by 5 cm-10 cm;
⑤ Paving and tensioning each section of isolation layer 7 with the thickness of 10-20 m, and backfilling the excavated trench with solidified soil;
Fourth, rolling solidified soil and curing
① After the solidified soil layer 3 and the isolation layer 7 are completed, the solidified soil layer is preliminarily compacted by using machines such as a light road roller in 1 d;
② In order to prevent the volatilization of water and the influence of rainwater in the curing process, paving 1 layer of plastic film on the surface of the cured soil layer 3 for curing;
③ After 14d, leveling the surface layer of the solidified soil layer 3 by using a light bulldozer or a man;
④ Testing and detecting the quality of the solidified soil layer 3, and meeting the design requirements;
Step five, paving geogrid
Spreading the geogrid 4 on the surface of the solidified soil layer 3, reserving the length of the pavement edge to be 80 cm-100 cm at the two ends, and overlapping each geogrid 4 with the length of 10 cm-20 cm;
Step six, filling the base layer
① Filling a first layer of slag or mud and crushed stone for 30 cm-50 cm, compacting by using a medium-sized road roller, wherein the solidity meets the design requirement;
② Folding the geogrid 4 at the edge of the reserved pavement back to place the top surface of the first layer of the slag or the mud-formed broken stone, continuously filling the second layer of the slag or the mud-formed broken stone for 30 cm-50 cm, and compacting by using a medium-or large-sized road roller until the slag or the mud-formed broken stone is filled and compacted to the design thickness, wherein the compactness meets the design requirement;
Step seven, paving the pavement
① Extracting cement nails of which the tops are temporarily fixed on a plurality of pile foundations 1;
② Paving an asphalt concrete pavement layer 6 or a paved stone pavement.
The examples of the present application are only for illustrating the present application and are not intended to limit the scope of the present application. It is also to be understood that various changes and modifications may be made by one skilled in the art after reading the teachings of the application, and that such equivalents are intended to fall within the scope of the application as defined in the appended claims.