How to learn the foundation of beam and plate raft?

In the beam plate raft foundation reinforcement and foundation beam reinforcement binding construction, the upper part of the foundation beam is a shear wall, and the raft plate reinforcement and the foundation beam gluten are crossed, and the relationship between its upper and lower arrangement is not clearly expressed in 11G101-3 and 09G901-3, but according to the force, the foundation beam is to bear the superstructure load transmitted by the wall column, and the superstructure floor beam and the plate stress is just opposite, according to this, it is inferred that the raft reinforcement should be below the foundation beam gluten reinforcement, and the same is true in the construction

Raft foundation (raft foundation), when the upper load of the building is large and the bearing capacity of the foundation is relatively weak, the simple independent foundation or strip foundation can no longer adapt to the needs of foundation deformation, which often connects the foundation under the wall or column into a piece, so that the load of the whole building is borne on a whole plate, and this full-hall plate foundation is called raft foundation. Due to its large bottom area, the raft foundation can reduce the base pressure, improve the bearing capacity of the foundation soil, and more effectively enhance the integrity of the foundation and adjust the uneven settlement.

The raft foundation is divided into flat plate type and beam plate type, which is generally determined according to the soil quality of the foundation, the superstructure system, the column spacing, the load size and the construction conditions.

Flat type. The floor of the slab raft foundation is a reinforced concrete slab of equal thickness. The thickness of the plate is generally between.

The slab foundation is suitable for the situation that the column load is not large, the column spacing is small and the column spacing is equal, and it is characterized by convenient construction and fast construction, but the amount of concrete is large. The thickness of the bottom plate can be preliminarily determined by adding 50mm to one layer, and then check the punching strength of the plate. The thickness of the bottom plate shall not be less than 500mm.

Usually for civil buildings with less than 5 floors, the board thickness is not less than 250mm; The plate thickness of a 6-storey civil building is not less than 300mm.

Beam and plate type. When the spacing between the column network is large, the beam-plate raft foundation is generally adopted. According to the setting of the rib beam, it is divided into two forms: one-way rib and two-way rib.

The one-way ribbed plate raft foundation is to connect two or more strip foundations under the column with a base plate in the middle to form a whole, so as to expand the bottom area of the foundation and strengthen the overall stiffness of the foundation. The two-way rib plate raft foundation is to arrange ribs under the columns in both longitudinal and transverse directions, and sometimes secondary ribs can also be arranged between the column nets to reduce the thickness of the bottom.

They are all raft foundations, and the beam-plate type is better than the zhi according to the stress condition

Flat raft foundation. It.

DAO is more reasonable. Raft foundation, pile foundation, and box-type foundation all have their own adaptation to the foundation bearing capacity, upper load, and building volume needs.

There are beams in the foundation of the beam-plate raft.

There are no beams in the foundation of a flat raft, it is a flat plank.

The slab-type raft foundation is a large slab, and the steel bars inside are similar to the plate reinforcements, one layer above and one layer below.

The beam-plate raft foundation is partially reinforced in the raft foundation, just like there are several beams, which are reinforced according to the form of the beam.

Summary. First, the meaning is different:

The slab type is a large thick slab underground, generally with dark beams, and the column directly transfers the load to the slab when working, which is a bit like a beamless floor;

The beam-plate type is to arrange two-way foundation beams under the columns, and plates are set between the beams. When working, the column transmits the load to the beam, and the beam is distributed to the slab, a bit like an inverted floor.

Second, the form is different:

The beams of the beam-plate raft foundation have webs that can be either on top or below. The earthwork excavation on the beam web is the same as the whole slab raft foundation, digging to the bearing layer to repair the leveling groove and then pouring the concrete cushion, leveling the waterproof layer, tying the steel bar, pouring the foundation.

The bottom of the raft is the contact surface between the raft and the cushion. Usually, the concrete cushion is poured on the bearing layer of the foundation, the waterproof layer is done, and the steel bar is tied on that surface and the concrete floor is poured, and the bottom plate is called the raft base plate (beam plate raft or flat raft).

The difference between a beam-plate raft foundation and a flat plate raft foundation.

Hello, I have seen your question and am sorting out the answer, please wait a moment.

First, the meaning is different: the slab type is a large thick plate underground, generally with dark beams, and the column directly transfers the load to the plate during work, a bit like a beamless floor; The beam-plate type is to arrange two-way foundation beams under the columns, and plates are set between the beams. During the work, the column transmits the load to the beam, and the beam is distributed to the plate, a bit like the inverted old brigade building.

Second, the form is different: the beam of the beam-plate raft foundation can be leaked on the top or below. The earthwork excavation on the beam web is the same as the whole slab raft foundation, digging to the bearing layer to repair the leveling groove and then pouring the concrete cushion, leveling the waterproof layer, tying the steel bar, pouring the foundation.

The bottom of the raft is the contact surface between the raft and the cushion. Usually, the concrete cushion is poured on the bearing layer of the foundation, the waterproof layer is done, and the steel bar is tied on that surface, and the concrete floor is poured, and the bottom plate is called the raft base plate (beam plate raft or flat raft board).

The beam-type raft foundation and the beam-free raft foundation area are different: different types of support, different beams and plates, and different applicable places.

1. Different types of support.

1. Beam-type raft foundation: support two forms: upper flat and lower flat rib beam.

2. Beamless raft foundation: support local thickened loose raft type.

Second, the beams and plates are different.

1. Beam-type raft foundation: those with beams and rafts connected together are called beam-type raft foundations.

2. Beamless ramming raft foundation: the one that is directly loaded by the plate on the independent foundation (or cushion cap) is the beamless raft foundation.

3. The applicable places are different.

1. Beam raft foundation: suitable for places where the bearing capacity of the foundation is uneven or the foundation is weak.

2. Beamless raft foundation: due to the simple construction, it is suitable for high-rise buildings.

Encyclopedia - Raft Basics.

Encyclopedia – Raft board.

Summary. Hello, glad to answer for you. Raft foundation construction:

1. Personnel preparation: Due to the large amount of concrete pouring, it takes about 50 hours to pour, so the concrete pouring personnel are divided into three groups, each group is equipped with no less than 40 construction personnel, and each group of management personnel is not less than 4 people.

Hello, glad to answer for you. Raft foundation construction: 1. Personnel preparation:

Because the amount of concrete pouring is larger, it takes about 50 hours to pour the banquet, so the concrete pouring personnel are divided into three groups, each group is equipped with construction personnel to do Xiangdong not less than 40 people, and each group of management personnel is not less than 4 people.

Hello, glad to answer for you. 2. Material preparation: The concrete is made of C40P10 waterproof concrete, which requires a mix ratio notice and a slump of 180mm 20mm; There are no less than 20 groups of concrete compressive mold test, and no less than 12 groups of impermeability test mold test; The insulated quilt is ready; Cover the parade with plastic film; 3. Preparation of machinery and tools

Concrete trucks, ground pumps, grinding pump pipes, concrete hoppers, vibrating rods (40 50 vibrating rods, 8 30 vibrating rods), ash buckets, shovels, iron trowels, wooden trowels, scrapers, plastic brooms, water pipes, rain boots, insulating gloves, etc.

1. In the plane layout of the raft foundation, try to make the center of gravity of the building coincide with the centroid of the raft foundation plane. The edge of the raft foundation should be picked out, and the width of the pick-out should be determined by the foundation conditions, the site conditions of the building, the column spacing and the size of the column load, so that the foundation reaction force coincides with the center of gravity of the building or minimize the eccentricity, and in general, the pick-out width is 1 4 1 3 of the side span column spacing.

2. The thickness of the raft foundation is determined by the punching shear resistance and shear strength, and at the same time, it is necessary to meet the impermeability requirements of the ridge foot, and when the local column spacing and column load are large, the pier can be added at the bottom of the plate under the column or a dark beam is set up and the stirrups are configured with anti-punching and careful seepage to increase the local shear resistance of the plate, so as to avoid thickening the entire raft due to a few columns. In addition to the strength check control, the raft foundation is also required to have a strong overall stiffness.

The general rule of thumb is that the thickness of the raft is estimated according to the number of floors on the ground, and each layer needs to be about 50mm 80mm thick. The project tower has 21 floors above ground, and the thickness of the raft is 1100mm; Part of the axial force of the column, the bottom of the column plate pier, the thickness of the column pier is 1600mm.

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Raft foundation application range.

The type of foundation used in the building is closely related to the type of foundation soil and the distribution of soil layer. In engineering design, such geological conditions are often encountered, and the rock and soil layer under the basement floor is a weathered residual soil layer, a fully weathered rock layer, a strong weathered rock layer or a medium weathered soft rock layer, so it is possible to use a natural foundation.

The basement of high-rise buildings is usually used as an underground parking garage, and too many interior walls are not allowed on the building, thus limiting the use of box-shaped foundations; The raft foundation can not only give full play to the bearing capacity of the foundation, adjust the uneven settlement, but also meet the space use requirements of the parking garage, so it becomes a more ideal foundation type.

The main structural types of raft foundation are flat raft foundation and beam plate raft foundation, and flat raft foundation is widely used in high-rise buildings due to its simple construction.