Analysis Of The Deformation Effect Of The Deep Excavation Adjacent To The Building

Deep excavation is usually located in the center of the city, and the surrounding environment is very complex, because there are a variety of buildings. This requires the excavation of foundation pit must meet not only the strength requirements, but also the deformation requirements. The design concept of pit foundation has also changed from strength control to deformation control. The rule of deformation of foundation pit will be different whether there are buildings adjacent to the excavation or not. Therefore, this paper studied the deformation of the excavation which is near to the buildings or surcharge. The main contents are as follows:1、The current situation at home and abroad of the rule of the deformation of the buildings and the foundation pit was summarized. And a brief description of the deformation mechanism of the excavation and the methods that forecast the deformation of the excavation and buildings were given.2、Three-dimensional model was established to analysis the law of the settlement of ground surface and the lateral displacement of retaining wall with FLAC3D. The profile of the settlement of ground surface is "groove type", and the lateral deformation pattern of the envelope pile is larger in the middle and smaller in the end. The spatial effect is obvious of the excavation. The location is closer to the corner of the pit, the deformation of the soil and the retaining wall is larger.3、The factors, such as the diameter of the piles, the distance between the piles and the horizontal spacing of anchor were considered the effect on the deformation of the excavation. With the increase of the pile diameter, both the settlement of ground surface and the lateral displacement of the piles are gradually reduced. Conversely, when the distance between the piles or the horizontal spacing of anchor increases, the deformation is increases.4、The deformation of the excavation was studied when the building is adjacent. The influence of the building on the he settlement of ground surface and the lateral displacement of the piles were studied. The profile of settlement of ground surface is still "groove type", but at the boundary of the building, the settlement has mutation because of the building. And the largest settlement does not occur in the soil beneath the building. The deformation of the excavation under overload was also compared. The ground surface settlement under overload is larger than that under the building, but the lateral displacement is almost same.5、The influence of the distance between the building and the pile, the gravity and the stiffness of the building was studied. With increasing the distance, behind the ground surface settlement and the horizontal deformation of envelope pile decreases. With the load of the building increases, the deformation increases. With the increase of the stiffness, the ground surface settlement decreases, while the lateral displacement of the piles increases.