Common Types of Foundation Support Methods in Building Construction

To ensure the safety of underground structure construction and the surrounding environment of the foundation, support, reinforcement, and protection measures are adopted for the side wall and surrounding environment. In recent years, due to the rapid development of urban foundation engineering, underground and foundation support have been widely studied. The unsafe support structure will certainly cause engineering accidents. Therefore, how to choose the appropriate supporting structure safely and reasonably and carry on the scientific design according to the characteristics of the foundation is the main content to be solved in foundation engineering.

 

Common types of foundations

1.    According to the used material can be divided into:

l  ash foundation

l  brick foundation

l  stone foundation

l  concrete foundation

l  reinforced concrete foundation

2.    According to the buried depth can be divided into:

l  shallow foundation

l  deep foundation

The buried depth is not more than 5m, called a shallow foundation, more than 5m is called a deep foundation.

3.    According to mechanical performance can be divided into:

l  rigid foundation

l  flexible foundation

4.    According to the structure form, it can be divided into:

l  strip foundation

l  independent foundation

l  raft foundation

l  pile foundation

The raft foundation also called box foundation.

 

Design requirements for foundation support

As a structural system, the foundation support should meet the requirements of stability and deformation, that is, the ultimate state of bearing capacity and the ultimate state of normal use.

The so-called ultimate state of bearing capacity refers to the failure of supporting structure, toppling, sliding or the destruction of the surrounding environment. The general design requirements do not allow the support structure to appear in this limit state.

The normal use limit state refers to the deformation of the supporting structure or the deformation process of surrounding soil caused by excavation, which affects the normal use but does not cause the instability of the structure. Therefore, the design of foundation pit support should have enough safety factor relative to the ultimate state of bearing capacity, so as not to cause the support instability, but also to control the displacement and not to affect the safety of surrounding buildings. As a design calculation theory, not only the stability of the supporting structure should be calculated, but also the deformation. And the deformation should be controlled in a certain range according to the surrounding environmental conditions.

 

The type of support

Sloped Excavation

Suitable for open sites, which no important buildings around and only requires stability support effect. The price is the cheapest kind of support.

Cement-soil Retaining Wall

A deep mixing soil-cement retaining wall is used to forcibly mix the soil and cement slurry in place by a deep mixing machine to form a continuous lap soil-cement column with a solid retaining wall.

The advantages of cement-soil retaining wall:

l  Because there is no reinforcement support in the foundation, the excavation is faster;

l  It has the dual function of retaining soil and sealing water.

l  Generally more economic;

l  No vibration, no noise, less pollution, and slight compaction in the construction, so the construction in the downtown area shows more advantages.

The disadvantages of cement-soil retaining wall:

l  The displacement is relatively large, so we can take the middle pier, arch, and other measures to limit the displacement;

l  The cement retaining wall is thick and can be used only when the surrounding environment allows it.

l  Moreover, attention should be paid to preventing the influence of the surrounding environment when the cement and soil mixing pile is constructed.

 


High-pressure Rotary Jet Grouting Pile

The high-pressure rotary jet grouting pile is one of the most widely used types in the soldier pile method. The characteristics of the high-pressure rotary jet grouting pile are: no vibration, no noise and other environmental hazards during construction. No compaction phenomenon, small impact on the surrounding environment; High wall strength, support stability, small deformation; Can be synchronized construction, short construction period;

 

Soil Nailing Wall

Soil nailing wall is a kind of slope stabilization support. Its role is different from the passive retaining wall, which plays an active embedded role to increase the stability of the slope and keep the slope stable after the excavation of the foundation pit.

 

Common Construction Materials

Soil nails

Soil nails are slender rods used to reinforce the soil and prevent the collapse and displacement of foundations or slopes.

 

Rock Bolt

Rock bolts are steel threaded rods that are inserted into rock mass to stabilize underground rock and soil structures during excavation. The anchorage structure formed by a rock bolt adopts a prestressed bolt group, which can transfer the tensile stress of the structure to the deep stable strata or reinforce the unstable rock mass, and form a bearing structure system in which rock bolt and rock mass interact and work together.

 

Self-drilling Anchor System

Compared with the general mortar bolt, the self-drilling anchor bolt developed rapidly in recent years and has obvious advantages. The self-drilling anchor system is composed of the hollow anchor bar, drill bit, coupling, centralizer, nut, and plate, which integrates drilling, grouting, and anchorage, making it more safe, more efficient, and more convenient. At present, the self-drilling anchor system is suitable for broken rock, loose rock, and other geology that is difficult to form holes and easy to collapse. It can greatly improve the supporting effect in complex geology and achieve the best construction effect.

 

 

About Sinorock Self-drilling Anchor System

Sinorock R thread self-drilling anchor bolt system is composed of a hollow rock bolt, anchor nut, anchor plate, anchor coupler, drill bit, centralizer, and the hollow anchor bars can be cut and lengthened by coupling on request.

Features and advantages:

1. Safe, reliable, and time-saving.

2. Simple installation & operation.

3. Choice of drill bits for different ground conditions.

4. Grouting works synchronize with drilling or after drilling. Grout can fill fractures effectively.

5. Anchor bars can be cut and lengthened on request, applying to narrow spaces.

6. It provides higher bonding stress than smooth steel pipe depending on continuous wave thread.

 

Summary

The above is the introduction of common support types of foundation and foundation engineering. If you have any questions about special formation construction, please feel free to contact us. Sinorock will provide you with a reliable solution.

 

 

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