Design of foundation and karst treatment for a residential project in a karst development area
With the rapid advancement of construction in China,the development of various buildings and structures in karst regions has been increasing. However,the challenges posed by karst geology cannot be overlooked,as it can lead to a series of serious engineering issues such as uneven foundation settlement,foundation collapse,and water leakage in basements. In extreme cases,karst may even result in the loss of foundation stability and structural damage. To effectively address these challenges,this study focused on a residential project in a karst development area within Zhejiang Province and conducted an in-depth discussion on the foundation design and karst treatment techniques of this project. The project comprises 8 high-rise residential buildings with 14 to 18 floors,a 2-3 story kindergarten,and single-story ancillary buildings,along with a one-level basement. Pile foundations were adopted for the main building sections,while a raft foundation was used for the single-level basement area. Considering the buoyancy issues in non-building areas of the basement,anti-floating anchors were employed,and the overall foundation design was rated as Class A. The geological investigation report revealed that the bedrock is soluble,with a cave occurrence rate of 16.6％,mostly in the form of point-like caves.Based on the relevant information above,this study elaborately discussed the foundation design schemes for different parts of the buildings and the basement. Based on the analysis of the base reaction forces under the buildings and the combination of engineering experience with geological conditions,bored piles with diameters of 800 mm and 1,000 mm were selected for the foundations beneath the buildings. After the solution of anti-floating pile was compared with the solution of rock anchor,anti-floating anchors for the conventional basement were planned to be used. For the construction of kindergarten,which required both load-bearing capacity and the ability to span caves,piles with the diameter of 600 mm were chosen as the anti-floating measure. Targeted research on treatment technologies for various types of caves was also conducted. Different karst treatment plans were formulated according to the height of the cave,whether it is ≤4 m for pile foundations or anchor traversals,or>4 m. This study provided construction considerations for cave treatment,including the adverse effects of caves on pile construction,the determination of the bearing stratum for engineering piles,and key matters such as pile testing. To ensure reliable karst treatment,quality inspections were equally important. These inspections confirmed that the cave treatment,integrity,and bearing capacity of the pile positions treated according to the principles outlined in this paper meet the code requirements,which can also validate the rationality of the results presented herein.Ultimately,this study has developed a comprehensive foundation design and karst treatment implementation plan for the project. Currently,there is a lack of discussion on the design of large-scale basements with flat rafts plus anti-floating anchors,and residential buildings with flat rafts plus bored piles in karst-developed areas. This study can provide certain reference for the design of related projects.
karstkarst treatmentfoundation designanti-floating anchor rodpile foundation
万方数据
维普
