Analysis of foundation treatment technology in high-rise building construction

Today, with the formation of large cities and megacities, the net inflow of urban population has increased significantly, and the plane and three-dimensional range of urban buildings has increased. As the most important development mode of urban space development, high-rise buildings have greatly alleviated the problems of urban land shortage and environmental congestion. In the construction of high-rise buildings, the foundation is an important foundation and premise, and it is also the guarantee for the safe construction and use of buildings. Therefore, it is necessary to scientifically treat the foundation of high-rise building projects and effectively improve the construction quality of high-rise building projects. Avoid unnecessary safety hazards in construction and subsequent use, which will affect social harmony and stability.

1 Significance of building foundation engineering technology

The foundation is the basic structure in construction engineering, which is used to bear the weight of the building and ensure the stability and safety of the building foundation, which is to ensure the performance of the overall building.

First, in the foundation construction of high-rise buildings, it is necessary to focus on the anti-deformation ability of the foundation, combined with the characteristics of the project, to ensure that the construction results meet the engineering standards, and to prevent serious safety hazards such as tilting in the later stage of the project. In the specific design, the designer needs to analyze the soil layer data information, plan the settlement value and bearing capacity of the foundation, and meet the engineering design requirements.

Second, the foundation is a hidden project of a high-rise building, and the quality of the foundation directly affects the overall quality of the building. In actual construction, the foundation is generally affected by many factors. Specifically, in some construction areas, geological conditions cannot provide favorable support, resulting in frequent geological disasters such as debris flows. In this regard, designers need to first survey the construction site environment, extract key data and information, and prepare design plans in a targeted manner. At the same time, make a detailed analysis of the problems that may arise in the later stage of foundation construction, and formulate solutions to problems in advance. During the construction process, the stability of the foundation is monitored throughout the process to avoid interference from negative factors to the greatest extent.

2 Analysis of characteristics of foundation construction in high-rise building construction

First of all, the foundation construction process is more complicated. my country has a vast territory and a large area, and the land and soil in different regions are also different. Therefore, in the construction of high-rise building projects, there will be relatively large differences in geological conditions. The existence of these differences requires that the foundation construction of high-rise building projects cannot be simply To use the same method, it is necessary to select the appropriate foundation treatment technology in combination with the specific geological environment. Therefore, the foundation construction technology of high-rise building projects has the characteristics of complexity and diversification.

Secondly, the foundation construction is related to the development of the subsequent construction process. In the construction of high-rise buildings, the foundation is the foundation and premise, and the effect of foundation construction treatment will directly affect the subsequent construction of high-rise buildings. If the ground treatment of high-rise building projects is unscientific and unreasonable, it will inevitably lead to the non-standardized development of subsequent construction, which will affect the final quality and effect of the entire high-rise building construction. For this reason, construction personnel of high-rise building projects need to clarify the close relationship between foundation construction and subsequent construction processes, use scientific foundation treatment technology, avoid unnecessary risks and accidents, and ensure orderly and high-level advancement of high-rise building construction .

Finally, the foundation construction of high-rise buildings is difficult. Compared with other projects, the foundation treatment of high-rise building projects is more difficult and has stricter requirements. If there is no strengthening of supervision, once technical problems and quality deviations occur during the construction process, it is impossible to remake or small-scale renovation. That is to say, if there are problems with the foundation and foundation of high-rise buildings, the economic loss will inevitably be huge.

3 Foundation treatment technology in high-rise building construction

3.1 Guarantee the accuracy of the setting-out measurement results

In the foundation construction of high-rise buildings, it is necessary to focus on the setting-out measurement work to ensure the accuracy of the setting-out measurement work results. At the same time, to ensure that the foundation construction has a good safety effect, safety supervision should be carried out, and wrong behaviors in personnel operations should be corrected in a timely manner, and the responsibilities of relevant personnel should be held accountable.

Specifically, during the setting-out measurement operation, it is necessary to strictly follow the requirements of the construction plan. Construction technicians first observe the actual situation of the measurement site, focus on collecting key data information, and can use laser collimator equipment and theodolite equipment for assistance. After that, the plane control baseline and the foundation elevation datum point are repeatedly checked to ensure the accuracy of the activity data to the greatest extent.

3.2 Construction preparation

In order to advance the construction of high-rise buildings in an orderly manner, the preparation before foundation construction is very important and critical. Special survey personnel should go to the area where the foundations of high-rise buildings are located to conduct detailed geological surveys and records, and formulate construction plans based on specific results. Different regions or different locations in the same region have different soil properties, so it is necessary to use differentiated construction techniques in order to achieve good construction results. Proper and reasonable preparation before construction can provide reliable reference for construction plan formulation and technical personnel's operation, and can respond to adjustments in time when changes occur during construction, so as to ensure the orderly progress of high-rise building projects. Before the foundation construction, it is necessary to carefully check the construction equipment and scientifically debug it. If any problematic equipment is found, it must be replaced in time. Strictly follow the relevant regulations for construction, improve the formulation of the management system in combination with the specific construction status, ensure the implementation of the responsibilities of each post, and make every effort to ensure the smooth progress of the foundation construction of high-rise construction projects.

3.3 Training staff

In the foundation construction of high-rise buildings, it is necessary to ensure that the personnel have good professional qualities. First of all, in the formation of the personnel team, do a good job in the quality assessment of personnel, ensure that the quality of personnel matches the job requirements, and optimize the organizational plan. Second, provide training and education to in-service personnel. In personnel training, actual cases can be imported, through case analysis, common problems can be sorted out, and problem solving methods can be summarized to help personnel accumulate effective experience and gradually improve personnel professional ability. Finally, improve the personnel management system. Responsibility mechanisms, reward and punishment mechanisms can be established, focusing on personnel behavior, and holding accountable for negative impacts caused by human factors to form a binding force. In addition, establish clear standards, norms and processes to provide behavioral guidelines for personnel operations.

3.4 Dynamic compaction treatment technology

At the construction site of high-rise buildings, different methods are used to analyze and detect the soil and foundation, and heavy hammers of different tonnages are used to compact the soft soil foundation, so that the density of the corresponding foundation area can be further scientifically maintained, and the soil quality can be improved. basic strength. The application principle of the dynamic compaction method is a dynamic consolidation principle in modern science. At the same time, it integrates the principle of dynamic compaction to further compact the fine particles and saturate the soil, and the original soft soil becomes stronger and destroyed through heavyweight pressure objects. The soil structure layer of the original soft soil foundation makes the gaps in it smaller, allowing the pore water in the foundation to be gradually discharged and consolidated and hardened under the pressure of the medium (heavy) hammer, thereby improving the overall bearing capacity of the foundation and laying a solid foundation for subsequent construction. Lay a solid foundation.

3.5 Concrete pouring

Concrete pouring is performed after the proportioning of concrete. Before the pouring operation, the construction personnel should carefully check whether there is debris at the bottom of the hole and clean it thoroughly. If there is excess water at the bottom of the hole, it is easy for the concrete to merge with the accumulated water during pouring, which will affect the overall quality of the concrete. So if there is a lot of water, you need to suck up the water. In addition, it is also necessary to pay attention to the height of pouring, so that the concrete pouring work can be advanced in an orderly manner. For concrete pouring, the following techniques are mainly involved. First, the technique of grouting reinforcement. Grouting reinforcement is to add grouting material to the solid matter, and fill the gap between the soil layer and the particles with gel material to strengthen the foundation. Most of the common grouting techniques for foundation treatment of high-rise buildings are flower pipes and buried pipes. It is necessary to grasp the actual geology. In order to achieve the best reinforcement effect, a variety of technologies are generally used in combination. Secondly, deep cement mixing pile treatment technology. In order to fully mix the cement, the mixing shaft impeller equipment should be used, and the operation should be carried out according to the following steps: first mix on the ground, open the valve after reaching the required depth, fully mix the cement and soil, and use the deepest mixing method to mix all materials. Furthermore, the basic treatment technology of high-pressure rotary spraying method. The high-pressure rotary grouting method is to turn the grouting pipe to the corresponding position through the drilling rig, use high-pressure equipment to disperse the grout around, damage the surrounding soil, and continuously rotate the rod to increase its speed. After the soil and the slurry are fully mixed, the slurry is solidified to form a solid knot and achieve the effect of reinforcement. Finally, cement fly ash gravel pile foundation treatment technology. This technology is widely used and is used in many construction projects. It is to add sand, fly ash and cement to the foundation, and then add water to stir it into piles. This technology is realized through mutual extrusion and exchange between piles.

3.6 Drainage and precipitation

Soil moisture content will have a certain impact on the stability and bearing capacity of the foundation. During the excavation of the foundation pit, it is necessary to establish a reasonable drainage system to ensure that the groundwater level is below 500mm of the foundation, and it is also necessary to prevent surface water and groundwater from seeping into the foundation pit. In general, the drainage methods mainly adopt the method of artificially lowering the groundwater level and the method of open drainage. When applying the open drainage method, it is necessary to arrange low-lying water collection wells, vertical and horizontal drainage ditches and other related facilities around the foundation pit, use the drainage ditch to guide and intercept the surface water, and then discharge it into the water collection well, and then use the water pump to implement drainage. However, this method cannot be applied to areas with a lot of groundwater. The reason is that the groundwater resources are relatively rich. During the excavation of the soil, if piping and quicksand occur, it is necessary to apply artificial well point precipitation treatment measures. Commonly used techniques Types include light well point precipitation method, electroosmosis well point method, jet well point precipitation method and other methods. In construction, the light well point dewatering method is basically applied, and the dewatering depth depends on the depth and number of well point pipes set, and the maximum depth reaches 12m.

3.7 Static pressure reinforcement method

Static pressure reinforcement technology refers to the technical means to achieve reinforcement operations with the help of professional equipment. In the actual operation process, the staff needs to manipulate the hydraulic equipment to configure the self-weight device, and use the gravity of the building as the reaction force to force the pile foundation into the soil layer, so as to reduce the gap between the soil layers and improve the compactness of the foundation. In addition, during the construction process, the operators also need to bury angle irons at the joints of the upper and lower segments of the pipe piles to realize the continuous operation of the static pressure piles. Since this technology requires the use of professional technical equipment to achieve reinforcement operations, relevant personnel need to determine the parameters of the piles in combination with the actual operating conditions during the operation. Once the piles are found to reach the specified load, the piles must be terminated in time, and the steel bars must be welded. The structure performs connection processing.

3.8 Prestressed pipe pile foundation treatment technology

Prestressed pipe pile foundation treatment technology is also widely used, and has achieved good results. The technology has pre-tensioning method and post-tensioning method. The common method of use is the pretensioning method. When using this method, in order to achieve the effect of the hollow cylinder, the centrifugal forming technology is generally assisted. Moreover, in order to advance the foundation treatment technology of prestressed pipe piles in an orderly manner, it is necessary to scientifically use the nature model of the steel sleeve. During the foundation construction, the direct excavation of the pile foundation should not occur as much as possible. The pile foundation should be excavated after 15 days of pile sinking. , When excavating, it is necessary to ensure that no damage is caused to the surrounding soil to prevent collapse. When excavating the foundation pit, the drainage work must be done first. When draining, it is necessary to leave a side slope at a specific position. The excavated earth cannot be placed directly next to it, because if its pressure is greater than the maximum value that the foundation pit can withstand, it will be easy. The collapse affected subsequent construction. In the prestressed pipe pile foundation treatment, pipe pile inclination is a very common construction problem, which will affect the quality of the foundation construction of the entire high-rise building. The reason for the pipe pile inclination is that the construction site has a small bearing capacity during foundation construction. , large slope, poor flatness and other problems, so the construction personnel should take reasonable countermeasures in advance to avoid the problem of pipe pile inclination. In order to properly deal with this problem, the construction personnel need to level the construction site and apply the technology of skidding within the working range of the pile driver to keep the pile driver in a stable state. During the construction, the construction personnel need to be conscientious and rigorous, and carefully check each construction link, so that the foundation treatment work can be carried out in an orderly and smooth manner.

3.9 Drainage consolidation method

This operation method mainly includes three aspects, which need to be reasonably used by relevant personnel in combination with the actual situation. First, surcharge preloading method. This technical means is to accumulate and reload the filling soil on the construction site to complete the settlement operation at the foundation level in advance. Because this technical means realizes the settlement and consolidation of the foundation in advance, it can significantly enhance the bearing capacity of the foundation. Moreover, this technology can also offset the original load pressure and eliminate the partial uniform settlement of the foundation, which is one of the common technical means at this stage. Second, the vacuum preloading method. This operation technique is to lay another layer of sand cushion layer on the clay layer, and then use a film to seal the soil layer, and form a negative pressure operation technique after pumping air. This technology can effectively discharge groundwater and avoid foundation settlement that may be caused by groundwater, which plays an important role in stabilizing the foundation. Third, the electroosmosis drainage method. This technology is also the main means of drainage, mainly through electroosmosis, and can also achieve stable foundation operations.

3.10 Follow the specification

Specifications are the rules that must be followed in foundation work and reinforcement work, and are also the work experience summed up by relevant personnel in practice, which can ensure the smooth development of work to a certain extent. First, follow the design specifications. The optimization and improvement of the foundation design of the building structure must meet the requirements of the design specification. Designers should study the specification carefully, carefully analyze and study the format and clauses in the specification, deeply understand the essence of the specification, and integrate the design specification into the foundation of the building structure. In the optimization of the design, only in this way can the reinforcement work be realized in a scientific and standardized manner. Second, strengthen the emphasis on computing. The reinforcement operation involves a lot of data, and the accuracy of the calculation results is also the guarantee for the smooth development of the reinforcement operation. Operators should pay attention to the calculation of various parameters and carry out construction in combination with relevant data. For working conditions that cannot be accurately calculated such as earthquakes, operators need to fully consider the damage caused by it, the structural foundation and corresponding structural measures, and ensure the scientific nature of the operation as much as possible.

in conclusion

In the construction of high-rise building projects, the foundation is an important foundation and premise. In order to ensure the construction effect of the entire high-rise building project, it is necessary to actively and scientifically use the foundation treatment technology. The high-rise building project itself has certain particularities, requiring construction personnel to comprehensively and carefully grasp every link of foundation treatment. In the actual construction of high-rise building projects, it is necessary to increase the emphasis on foundation construction, and adopt diversified treatment technologies to improve the stability of the foundation, so as to provide guarantee for the realization of the overall quality effect of high-rise building projects.