In recent years, the scale of China's construction projects has continued to expand, and the construction quality of building projects has also been continuously improved. However, in actual construction processes, especially in the construction of building foundation engineering, there are still some areas that need improvement. Therefore, relevant departments should strengthen the improvement of construction techniques and technologies.
　　1. Basic Situation of Current Foundation Engineering Construction
　　1.1 The diversity of China's geographical environment and conditions determines that in the construction process, a thorough study and inspection of the terrain and landforms should be conducted.
　　1.2 At present, with the increase in the number of construction projects, various building collapses and safety accidents caused by foundation construction problems have also occurred from time to time. Therefore, in order to ensure the personal safety of residents and construction personnel, relevant departments should also strengthen strict quality control of foundations.
　　1.3 In the construction process of building projects, it is also necessary to connect and handle various construction projects and procedures. Once there are quality or technical problems in the previous construction step, the continuation of the next construction step may lead to faults or temporary concealment, thereby forming potential safety hazards.
　　1.4 The construction characteristics of foundation engineering itself also determine that it is easy to conceal some quality problems and defects during the construction process. Once construction is completed, if safety problems occur during the completion or use of the building, they will lead to relatively serious faults or safety accidents. Therefore, in the process of quality management and control of foundations, potential threats should be detected and eliminated based on experience.
　　2. Common Faults and Causes of Foundation Engineering
　　2.1 Cracks in Concrete Structures of Foundations
　　In the construction process of building foundations, quality problems in concrete structures are relatively common. That is to say, strengthening the crack control of concrete structures can effectively improve the quality of foundations. The main reasons for concrete structure cracks in China's construction projects during construction are as follows: First, inconsistent placement of concrete sleepers during construction leads to uneven stress and cracks; Second, inadequate curing during construction causes rapid water evaporation and cracks.
　　2.2 Water Leakage Problems in Building Foundation Engineering
　　In the process of foundation construction, water leakage in some structures is also an important reason affecting the quality of foundations. Generally speaking, water leakage is more likely to occur at eaves, gables, and deformation joints. Possible causes include human factors in the implementation of construction techniques and changes in the external natural environment.
　　2.3 Substandard Construction Materials for Building Foundation Engineering
　　In the construction process of building projects, especially in the construction of foundation engineering, if the selected construction materials are substandard, cannot meet the corresponding construction needs, or do not meet the relevant national quality certification standards, they will have a very adverse impact on the quality of the project.
　　2.4 Blockage of Ventilation Ducts in Building Foundation Construction
　　Generally speaking, in the construction process of building foundation engineering, the cause of ventilation duct blockage may be unreasonable structural design in the design stage. Therefore, in order to solve this problem, relevant departments must strengthen the supervision of the design phase of building foundations.
　　3. Measures to Improve the Construction of Building Foundation Engineering
　　3.1 Strengthen the Selection of Existing Foundation Construction Types for Building Projects
　　As the primary construction item of a project, the foundation is the transition section connecting the building and the ground. Therefore, the construction quality of the foundation determines, to a certain extent, the construction quality of the building project. Therefore, in the process of construction management, relevant departments should pay attention to the selection of existing foundation construction methods, because different building forms and different geological conditions have different requirements for the function and strength of foundations. Therefore, relevant design departments should strengthen the selection management in construction plans.
　　Generally speaking, for soft soil foundation construction, relevant soil treatment work should be done during construction, that is, the existing soft soil should be reinforced. In other words, the properties of the existing soft soil can be neutralized through the strength of concrete.
　　3.2 Attach Importance to the Management of Construction Technology and Techniques for Building Foundations
　　In the process of selecting construction methods and techniques, relevant departments should also fully consider the adaptability of existing foundations. That is to say, the existing soil conditions should be investigated and analyzed, and the filling method should be selected. Generally speaking, common methods such as replacement and filling of the base layer, cement-fly ash gravel pile method, lime pile method, dynamic compaction method, vibroflotation method, cement-soil mixing method, high-pressure jet grouting method, preloading method, compacted cement-soil pile method, water-sand-gravel pile method, lime-soil compaction pile method, and soil compaction pile method can be used for construction. The selection of different construction methods should be based on actual foundation conditions and fully consider the needs of building construction.
　　The building foundation treatment plan should comprehensively consider engineering geological and hydrogeological conditions, building form and functional requirements, load size and distribution, adjacent building foundation conditions, construction conditions and material supply, and regional seismic intensity, and select a reasonable foundation form. Combined with the actual situation of the foundation (poor foundation, large load), the integrity should be enhanced and uneven settlement reduced before construction. To meet foundation and settlement requirements, pile foundations or artificially treated foundations can be used. Manual excavated piles are suitable for deep groundwater levels and no flowing muddy soil above the bearing layer. Therefore, using pile foundations as the foundation of this building is relatively ideal. We should focus on the adverse effects of excessive length on the structure. When increasing the spacing of structural expansion joints or not setting expansion joints, practical measures must be taken to prevent structural cracking. Among various measures to appropriately increase the maximum expansion gap, taking crack prevention measures during the structural construction stage is a common and effective method to reduce the adverse effects of concrete shrinkage. The commonly used approach is to set construction post-cast strips. When the basement structure is excessively long and post-cast strips alone are insufficient to solve the problems of concrete shrinkage and temperature changes, shrinkage-compensating concrete can be considered, with expansion reinforcement bands set at appropriate positions, and strict technical safeguard measures formulated to ensure the quality of concrete raw materials and the accurate mix ratio of micro-expansion agents. Structural design should take measures for the restrained expansion rate of concrete in basement structural parts. In construction, whether to set permanent deformation joints between the main body of high-rise buildings and podiums, or to set settlement post-cast strips during the construction stage, should be comprehensively determined based on the soil conditions of the foundation bearing layer, foundation form, superstructure layout, and other conditions. When using natural foundations, the embedment depth should generally be at least 2m greater than the podium foundation embedment depth. If requirements are not met, the stability of the high-rise building should be calculated and connected with the elevated floor of the high-rise building, with settlement joints set during the period. The foundation embedment depths are basically the same, and the settlement joints are filled with hard materials. If handled improperly, problems of mutual quality between high-rise building floors and underground elevated floors may occur. After the building is put into use, cracks may appear on both sides of the settlement joint walls, causing leakage.
　　In recent years, composite foundations have been widely used because of their obvious effects in improving the continuous bearing capacity of foundations and controlling the settlement of building entities. However, regardless of the method used, in addition to emphasizing construction procedures, materials, and management, scientific and reasonable construction plans must first be ensured. This is the key to the quality and safety of building projects.
　　Conclusion
　　In summary, quality is the foundation of a century-long plan. The quality of building projects is related to people's daily life and the safety of life and property. Therefore, relevant departments should strengthen the construction quality control of building projects, especially the construction quality control of building foundations, because the construction quality of foundations directly determines and affects the construction quality of the entire building project. Therefore, in the construction of building foundation engineering, quality management is the key and core. Only by doing a good job in quality supervision and management of building projects can more high-quality projects be built, thereby ensuring the durability of buildings and the safety of people's lives and property.