CN100999172A - Construction method of artificial landscape mountain - Google Patents

Abstract

The present invention discloses an artificial landscape mountain body construction method. Said construction method includes the following steps: on the ground surface to be used laying cement-lime mixture layer with a certain thickness, then on the cement-lime mixture layer laying and building geotechnical grille, on the described geotechnical grille further laying and building cement-lime mixture layer so as to form a reinforced cement-lime mixture layer with a certain strength, after said reinforced cement-lime mixture layer is hardened to form a reinforced hard shell, on the reinforced hard shell layer building mountain body.

Description

Artificial landscape mountain construction method

technical field

The invention relates to the field of horticultural construction, in particular to a method for constructing artificial landscape mountains.

technical background

In order to satisfy people's desire for natural gardens, in the design and construction of modern gardens, artificial landscape mountains appear more and more frequently to form undulating terrain and create the atmosphere of natural gardens. In landscape design, since the overall settlement of the mountain has little impact on the environment and landscape, the design and construction of artificial landscape mountains are mainly affected by the overall stability of the mountain. However, in soft soil areas (such as Shanghai), due to poor foundation soil quality and low strength, although there may be a hard crust on the ground surface, the hard crust is often thin and not high in strength. When filling higher mountains, landslides often occur when the stability of the mountains does not meet the design requirements, causing major accidents (such as the landslide in Shanghai Pudong Century Park). The reason is mainly caused by the imbalance of the mountain force. As shown in Figure 1, a simple analysis of the stress status of the mountain:

1. Simplify the mountain A above the ground G into multiple continuous analyzed soil strips A1, A2, A _i , A _i+1 , An, and the unstable landslide of mountain A is thus simplified into soil strip A1 , A2,, A _i , A _i+1 ,, An arc sliding from top to bottom, and the sliding angle of soil bar A _i is α _i ;

2. Taking the soil strip A _i as an example, the sliding moment Ms generated by the soil strip A _i due to the decomposition force T _i of the self-weight W _i relative to the center O of the sliding surface;

3. The strength of the soil strip A _i mainly depends on the cohesion force and the internal friction angle, and the shear force τ _fi along the tangential direction is formed on the arc contact surface;

4. The shear force of the soil strip A _i acts on the arc contact surface, and there is a stabilizing moment Mr against sliding relative to the center O of the slope;

5. The stability of the mountain A depends on the relationship between the sliding moment Ms and the stabilizing moment Mr.

From the above analysis, it can be seen that the effective means to improve the stability of the mountain is to reduce the sliding moment Ms and/or increase the stabilizing moment Mr.

There are also multiple existing technologies for solving the problem of mountain slope instability. In particular, as shown in Figure 2, in order to solve the problem of instability of artificial mountain slopes, a technical solution combining composite foundation B and lightweight material C is widely used in the prior art. The technical solution is analyzed as follows:

1. Treat the ground G with the composite foundation B to increase the strength of the foundation (thick line part) on the ground G and increase the resistance moment Mr, thereby improving the stability of the mountain.

2. Fill the mountain body with light material C (such as EPS, ultra-light building material, high cost), reduce the gravity of the soil strip Ai, reduce the sliding moment Ms, thereby improving the stability of the mountain body.

The use of the composite foundation B in the above-mentioned technical solution requires relatively large costs, not only high processing costs, but also has a certain impact on the surrounding environment. The cost of lightweight material C is generally higher, which will obviously increase the cost of artificial landscape mountains. Therefore, the construction method of the artificial landscape mountain in the prior art obviously needs further improvement.

Contents of the invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a method for constructing artificial landscape mountains with low cost, good stability and no environmental pollution.

In order to achieve the above object, the invention provides a method for building an artificial landscape mountain, comprising the following steps:

First, pave a certain thickness of fly ash layer on the ground to be used;

Then, laying a geogrid on the fly ash layer, and laying a fly ash layer on the geogrid again to form a reinforced fly ash layer with a certain strength;

Finally, after the reinforced fly ash layer is dried to form a reinforced hard shell layer, mountains are piled up on the reinforced hard shell layer.

Preferably, in the fly ash layer, multiple layers of the geogrid are laid alternately at intervals to form the reinforced fly ash layer.

Preferably, the thickness and strength of the reinforced hard shell and the number of layers and thickness of the geogrid are selected according to the mountain stability safety factor K, and the calculation formula of the mountain stability safety factor K is:

$\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\mathrm{<span\; class="notranslate">\; tg</span>}{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; R</span>}\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}{\mathrm{<span\; class="notranslate">\; R</span>}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}$

Preferably, the calculated mountain stability safety factor K is too small, increase the thickness and strength of the reinforced hard shell, or increase the number of layers and strength of the geogrid, and recalculate the mountain stability Safety factor K until the calculated mountain stability safety factor K meets the stability requirements.

Preferably, when the calculated safety factor K for the stability of the mountain body is too large, in order to increase the economy of the mountain body treatment, reduce the thickness and strength of the reinforced hard shell layer, or reduce the number of layers of the geogrid , strength, and recalculate the mountain stability safety factor K until the calculated mountain stability safety factor K meets the stability requirements.

Preferably, the foundation of the predetermined construction area is leveled to form the ground to be used.

Preferably, the fly ash layer is the fly ash plus lime layer, and the conventional formula is 95% fly ash: 5% lime.

Preferably, an appropriate amount of binder is mixed in the fly ash layer.

Preferably, the geogrid is chemical fiber warp-knitted geogrid or polypropylene geogrid, and its tensile strength is 20-50kN/m at 10% strain.

In the artificial landscape mountain construction method of the present invention, at first a reinforced hard shell layer is paved on the ground, similar to a reinforced concrete slab, and the reinforced hard shell layer has fully utilized the high compressive strength of the fly ash material, and the Shigongge The high tensile strength and other characteristics of the grid greatly increase the strength of the foundation of the artificial landscape mountain, thereby increasing the resistance moment that the mountain slope needs to overcome and improving the stability of the mountain.

At the same time, since the self-weight of the fly ash material used to construct the hard shell is lighter than that of the filling soil, the gravity of the mountain is reduced, which reduces the magnitude of the sliding moment that causes the slope of the mountain to slide, and at the same time improves the stability of the mountain.

Due to the light weight of fly ash, it can reduce the additional stress of the base, thereby reducing the settlement of the mountain. In addition, due to the high strength and high rigidity of the reinforced hard shell, it can significantly improve the basin-shaped settlement of the mountain and reduce the maximum settlement of the center point of the mountain. The above two aspects have improved the settlement of the mountain, thereby reducing the impact of the settlement on the surrounding environment and the overall landscape.

On the other hand, because the fly ash material and the geogrid are low in cost and have no environmental pollution, and the construction technology is mature and convenient, the method of the present invention also has the technical effect of reducing the cost of artificial landscape mountains.

The idea, specific steps and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

Description of drawings

Fig. 1 is the force analysis diagram of mountain slope instability;

Fig. 2 is a force analysis diagram of a technical solution in the prior art;

Fig. 3 is a force analysis diagram of a mountain slope according to the method of the present invention.

Detailed ways

As shown in Figure 3, it is a force analysis diagram of a mountain slope in a specific embodiment of the present invention, and the artificial landscape mountain construction method of the present invention comprises the following steps:

Generally, the foundation of the planned construction area is first leveled to form the ground G to be used;

Then, lay a fly ash layer of a certain thickness on the ground G to be used, that is, a fly ash plus lime layer, and lay geogrids E ₁ , E _j , E _m at intervals of a certain thickness in the fly ash layer;

Thereafter, after the above-mentioned fly ash and lime layer are dried to form a reinforced hard shell D, the mountain body A is piled up on the reinforced hard shell D.

The aforementioned fly ash plus lime layer is a commonly used fly ash material in the field, and the conventional formula is 95% fly ash: 5% lime. In order to improve its cohesion, it is also possible to add a certain proportion of binder or increase the amount of lime. Geogrid is also a commonly used geotechnical material in engineering.

In a specific embodiment of the present invention, the force of the mountain A is analyzed by taking the soil strip A _i and the geogrid E _j as examples. The soil bar A _i produces a sliding moment Ms along the arc contact surface D _i of the mountain A relative to the center O of the sliding arc due to the decomposition force T _i of its own weight W _i . The strength of the soil strip A _i mainly depends on its own cohesion and internal friction angle. The shear strength τ _fi along the tangential direction is formed on the arc contact surface D _i , and the tensile force of the geogrid E _j along the arc contact surface D _i produces component force P _j in the tangential direction, the shear force of soil strip A _i and the component force P _j of geogrid E _j act on the arc contact surface D _i , and there is a stabilizing moment Mr against sliding relative to the center of circle O . When the sliding moment Ms is greater than the stabilizing moment Mr, the mountain will be driven by the sliding moment Ms to slide down along the circular sliding surface, forming a landslide on the mountain A; when the sliding moment Ms is not enough to overcome the stabilizing moment Mr, the mountain will maintain good stability Will not slide. Therefore, the stability of the mountain A depends on the relationship between the sliding moment Ms and the stabilizing moment Mr. In theory, if the sliding moment Ms is greater than the stabilizing moment Mr, the mountain A will have a landslide, and the stabilizing moment Mr is greater than the sliding moment Ms, then the mountain A will remain stable. . In practical application, taking into account other factors affecting the mountain body, there should still be some leeway for the stabilizing moment.

In the prior art, in the field of construction engineering, the high strength and hardness of the fly ash material after drying is generally fully utilized as the foundation of the highway, so as to maintain the relative stability and smoothness of the highway foundation and the surrounding environment foundation. Compared with the road foundation, the stability of the mountain foundation is far more important than the settlement of the mountain foundation. The important difference between the present invention and the prior art is that the present invention adopts the technical means of paving the fly ash reinforced hard shell, and uses the high strength and hardness of the fly ash material to solve the stability inside the mountain foundation. The stability of the mountain is improved by increasing the resistance moment and reducing the sliding moment.

A beneficial effect of the artificial landscape mountain construction method of the present invention is that, since a reinforced hard shell is paved on the ground first, the strength of the foundation of the artificial landscape mountain is greatly increased, thereby increasing the resistance to be overcome when the slope slides The size of the moment improves the stability of the mountain. Since the reinforced hard shell is paved on the existing ground G, there will be no construction waste caused by excavating the foundation and no pollution to the environment.

Another beneficial effect of the present invention is that, since the self-weight of the fly ash material for constructing the reinforced hard shell is about 1/4 lighter than that of the original soil strip, the self-weight _Wi of the mountain body A becomes smaller thereupon, thereby implementing the method of the present invention to build The artificial landscape mountain reduces the gravity of the sliding body, reduces the sliding moment that causes the slope of the mountain to slide, and improves the stability of the mountain.

Another beneficial effect of the invention is that, due to the light weight of the fly ash, the additional stress on the base can be reduced, thereby reducing the settlement of the mountain body. In addition, due to the high strength and high rigidity of the reinforced hard shell, it can significantly improve the basin-shaped settlement of the mountain and reduce the maximum settlement of the center point of the mountain. The above two aspects have improved the settlement of the mountain, thereby reducing the impact of the settlement on the surrounding environment and the overall landscape.

At the same time, the beneficial effect of the present invention lies in that the method of the present invention can also reduce the cost of artificial landscape mountains due to the low cost of fly ash material and geogrid without environmental pollution, mature and convenient construction technology.

The calculation principle of the method of the present invention is described in detail below, particularly the analysis of the thickness of the reinforced hard crust and the stability of the mountain side slope:

After the reinforced hard shell layer is set, the principle of stability calculation is basically the same as that of conventional slope stability calculation, and the weight γ and strength indexes c and φ of the soil layer are also input in layers, mainly to determine the design requirements by laboratory tests in advance Under the degree of compaction (generally 90% of light compaction standard), the heavy γ and strength index c, φ of fly ash (generally 5% lime + 95% fly ash) and the pre-set tensile strength of geogrid N.

Calculation conditions:

1. Calculate the strength c _i and φ _i at the arc contact surface of soil strip i.

2. The weight W i of the soil strip calculated from the weighted average weight γ _i of each layer of the soil strip _i .

3. Tensile strength N of geogrid, component force in tangential direction P _j = Ncosα _i .

calculation process:

1. Assume that the slope slides according to the center O and radius R.

2. Calculate the sliding moment Ms and stabilizing moment Mr generated by the force on the soil strip i on the center O:

Ms＝W _i Rsinα _i

Mr＝(W _i cosα _i tgφ _i +c _i l _i +p _j )R

Where l _i is the arc length of the soil strip.

3. Calculate the stability safety factor of the entire mountain corresponding to the sliding surface as follows:

$\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; tg\&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; R</span>}\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}{\mathrm{<span\; class="notranslate">\; R</span>}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}$

4. Constantly adjust the circle center O and radius R, and search and calculate the minimum value of the stability safety factor K.

5. The calculated minimum value of K is the safety factor of mountain slope stability.

6. If K does not meet the specification requirements, increase the thickness and strength of the reinforced hard shell, or increase the number and strength of geogrid layers, and recalculate the safety factor.

7. If the stability and safety are too conservative, appropriately reduce the thickness and strength of the reinforced hard shell, or reduce the number and strength of the geogrid to reduce the project cost.

According to the above-mentioned analysis and calculation, by choosing the size of different K values, the thickness of the reinforced hard shell selected in the specific embodiment of the present invention, the strength and the number of layers, the strength of the geogrid, etc. can be determined, so that the constructed artificial landscape The stability of the mountain meets the design requirements.

To sum up, what is described in this specification are only several preferred specific embodiments of the present invention. All technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the protection scope of the claims of the present invention.

Claims (9)

1, a kind of construction method of artificial landscape mountain may further comprise the steps:

At first, certain thickness two grieshoch of making on stand-by ground;

Then, making GSZ on described two grieshoch, and on described GSZ making two grieshoch once more, with reinforcement two grieshoch that form certain intensity;

At last, treat the dry and hard formation one reinforcement crust layer of described reinforcement two grieshoch after, heap is built massif on described reinforcement crust layer.

2, the method for claim 1 is characterized in that, in described two grieshoch, spacing ground is the described GSZ of making multilayer alternately, to form described reinforcement two grieshoch.

3, the method for claim 1 is characterized in that, chooses the number of plies, the thickness of thickness, intensity and the described GSZ of described reinforcement crust layer according to massif buckling safety factor K, and the computing formula of described massif buckling safety factor K is:

$K=\frac{M_r}{M_s}=\frac{R\underset{i=1}{\overset{i=n}{\mathrm{\&Sigma;}}}(W_i\cos {\mathrm{\&alpha;}}_i\mathrm{tg}{\mathrm{\&phi;}}_i+c_i{l}_i)+R\underset{j=1}{\overset{j=m}{\mathrm{\&Sigma;}}}{p}_j}{R\underset{i=1}{\overset{i=n}{\mathrm{\&Sigma;}}}{W}_i\sin {\mathrm{\&alpha;}}_i}$

4, method as claimed in claim 3, it is characterized in that, when the described massif buckling safety factor K that calculates is less than normal, increase thickness, the intensity of described reinforcement crust layer, perhaps increase the number of plies, the intensity of described GSZ, recomputate described massif buckling safety factor K, meet stability requirement until calculating the described massif buckling safety factor K that obtains.

5, method as claimed in claim 3, it is characterized in that, when the described massif buckling safety factor K that calculates is bigger than normal, for increasing the economy that massif is handled, reduce thickness, the intensity of described reinforcement crust layer, perhaps reduce the number of plies, the intensity of described GSZ, recomputate described massif buckling safety factor K, meet stability requirement until calculating the described massif buckling safety factor K that obtains.

6, the method for claim 1 is characterized in that, the ground of smooth predetermined build area forms described stand-by ground.

7, method as claimed in claim 1 or 2 is characterized in that, described two grieshoch are that flyash adds lkd layer, and conventional formulation is a flyash 95%: lime 5%.

8, method as claimed in claim 7 is characterized in that, is mixed with the binding agent of appropriate amount in described two grieshoch.

9, method as claimed in claim 1 or 2 is characterized in that, described GSZ is chemical fibre warp knitting geogrid or polypropylene GSZ, and tensile strength is 20～50kN/m during 10% strain.

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