Soft soil composite foundation structure based on foam concrete

Abstract

The utility model relates to a soft soil composite foundation structure based on foam concrete. The soft soil composite foundation structure comprises a pavement structure layer, a graded gravel cushion layer and a pile composite foundation pile which are distributed from top to bottom. A foam concrete cushion layer is arranged between the pavement structure layer and the graded sandstone cushion layer, and the foam concrete cushion layer and the graded sandstone cushion layer form a composite cushion layer. According to the utility model, the foam concrete is a body with certain thickness and bonding strength, so that when soft soil between the piles is poor in property and excessively settles, the foam concrete cushion layer can share and transfer the load at the upper part to the pile tops of the composite foundation piles; when the property of the soft soil between the piles is relatively good, the graded gravel cushion layer can play a role to share and transfer part of the upper load to the soil between the piles, and the bearing capacity of the soil between the piles is utilized. Therefore, the composite cushion layer can effectively coordinate the settlement difference between the piles and the soil and efficiently guarantee the ground flatness.

Description

Technical Field

[0001] The utility model relates to the field of foundations, in particular to a soft soil composite foundation structure based on foam concrete. Background Art

[0002] At present, composite foundation treatments such as cement mixing piles, high-pressure jet grouting piles, and CFG piles are often used for roads on deep soft foundations with settlement and bearing capacity control requirements; their general structure from top to bottom is the pavement structure layer, graded sand and gravel cushion layer, and reinforced pile composite foundation layer. However, it is not uncommon for the treated roads to become uneven or sink too much overall after a period of operation.

[0003] Generally speaking, uneven road settlement is often caused by the settlement difference between the composite foundation piles and the soft soil between the piles. The existing scheme generally reduces the road settlement difference by increasing the density of composite foundation piles, thickening the crushed stone cushion layer, and adding geotechnical reinforcement materials to the crushed stone cushion layer. If the post-construction settlement of the road is too large, it is generally controlled by increasing the density of composite foundation piles and lengthening the piles.

[0004] However, if the composite foundation piles are increased in density, the cost will increase significantly; and if the graded sand and gravel cushion layer is thickened or geotechnical reinforcement materials are added, the effect of uneven settlement control is limited because the cushion layer is still made of loose materials.

[0005] Similarly, if the settlement is too large, the use of dense composite foundation piles will also cause a significant increase in costs; and if the pile length is increased to control it, the type of pile needs to be considered; the more economical mixing pile has a limited treatment depth, and when the silt thickness is too large, the treatment depth of the mixing pile cannot meet the settlement control requirements. If CFG piles with a larger treatment depth are used, the cost will increase significantly. Summary of the invention

[0006] The purpose of the utility model is to provide a soft soil composite foundation structure based on foam concrete, which can well share and transfer the load to the composite foundation piles by adding a foam concrete cushion layer, reduce or avoid effectively coordinating the settlement difference between the piles and the soil, and efficiently ensure the flatness of the ground.

[0007] The utility model is realized by the following technical scheme: a soft soil composite foundation structure based on foam concrete, comprising a pavement structure layer, a graded sand and gravel cushion layer and a pile composite foundation pile distributed from top to bottom. A foam concrete cushion layer is arranged between the pavement structure layer and the graded sand and gravel cushion layer, and the foam concrete cushion layer and the graded sand and gravel cushion layer form a composite cushion layer.

[0008] Compared with the previous technology, the beneficial effects of the utility model are:

[0009] 1. Foamed concrete is a bonded strength body with a certain thickness. When the soft soil between piles is of poor quality and excessive settlement occurs, the foamed concrete cushion layer can transfer the upper load to the top of the composite foundation pile; when the soft soil between piles is of relatively good quality, the graded sand and gravel cushion layer can play a role in transferring part of the upper load to the soil between piles, making use of the bearing capacity of the soil between piles. Therefore, the composite cushion layer can effectively coordinate the settlement difference between piles and soil, and efficiently ensure the flatness of the ground.

[0010] 2. The bulk density of lightweight foam concrete is significantly lower than that of general surface miscellaneous (plain) fill layers. By over-digging the existing surface soil layer and replacing it with lightweight foam concrete, the self-weight stress of the foundation is reduced, and the additional net pressure acting on the top of the composite foundation is reduced. The foundation settlement under the same additional ground load is smaller than that of the traditional composite foundation. And when the depth of the composite foundation pile treatment has reached the limit, the post-construction settlement can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the utility model;

[0012] Figure 2 It is a schematic diagram of the soil layer corresponding to the utility model.

[0013] Explanation of numbers: 1 pavement structure layer, 2 graded sand and gravel cushion layer, 3 composite foundation piles, 4 foam concrete cushion layer. DETAILED DESCRIPTION

[0014] The utility model is described in detail below in conjunction with the accompanying drawings:

[0015] like Figure 1 As shown: A soft soil composite foundation structure based on foam concrete, comprising a pavement structure layer 1, a graded gravel cushion layer 2 and a pile composite foundation pile 3 distributed from top to bottom. A foam concrete cushion layer 4 is provided between the pavement structure layer 1 and the graded gravel cushion layer 2, and the foam concrete cushion layer 4 and the graded gravel cushion layer 2 form a composite cushion layer.

[0016] Here, the foam concrete cushion layer can transfer the upper load to the top of the composite foundation pile. When the soft soil between the piles is relatively good, the graded sand and gravel cushion layer can play a role in transferring part of the upper load to the soil between the piles, and utilize the bearing capacity of the soil between the piles. That is to say, the composite cushion layer formed by the foam concrete cushion layer 4 and the graded sand and gravel cushion layer 2 can effectively coordinate the settlement difference between the pile and the soil, and efficiently ensure the flatness of the ground.

[0017] The foam concrete cushion layer 4 is a lightweight foam concrete cushion layer, which can effectively reduce costs.

[0018] The thickness of the graded sand and gravel cushion layer 2 is 200-300 mm, which is the same as the traditional thickness.

[0019] The thickness of the foamed concrete cushion layer 4 is not less than 1000 mm. The thickness here is determined according to the depth of the temporary trench for easy excavation, the load reduction requirement and the load sharing and transfer requirement.

[0020] The pavement structure layer 1 is generally 300-700 mm thick, which is also the same as the traditional thickness.

[0021] The pavement structure layer 1 is mainly composed of cement-stabilized crushed stone, concrete or asphalt, and the material is the same as that of traditional methods.

[0022] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A soft soil composite foundation structure based on foamed concrete, comprising a pavement structure layer (1), a graded sand and gravel cushion layer (2) and a pile composite foundation pile (3) arranged from top to bottom, characterized in that: A foamed concrete cushion layer (4) is provided between the pavement structure layer (1) and the graded sand and gravel cushion layer (2), and the foamed concrete cushion layer (4) and the graded sand and gravel cushion layer (2) form a composite cushion layer.

2. The soft soil composite foundation structure based on foamed concrete according to claim 1, characterized in that: The foam concrete cushion layer (4) is a lightweight foam concrete cushion layer.

3. The soft soil composite foundation structure based on foamed concrete according to claim 1, characterized in that: The thickness of the graded sand and gravel cushion layer (2) is 200-300 mm.

4. The soft soil composite foundation structure based on foamed concrete according to claim 1, characterized in that: The thickness of the foamed concrete cushion layer (4) is not less than 1000 mm.

5. The soft soil composite foundation structure based on foamed concrete according to claim 1, characterized in that: The pavement structure layer (1) is 300-700 mm thick.

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