Determination of Embedded Depth of Soldier Piles in Pile-Anchor Supporting System in Granite Residual Soil Area

Abstract

Reasonable depth of pile embedment is one of the key factors for the success of deep foundation pit projects. This paper has taken a deep foundation pit project in a granite residual soil area in Shenzhen as an example and used physical model tests to study the deformation law of the piles and the surrounding soil during the excavation of the deep foundation pit, revealing the variation law of earth pressure in time and space in the pit and then verified it by numerical simulation. The influence of the embedded depth of the pile on the deformation and earth pressure of the deep foundation pit is then explicitly discussed. The study shows that the embedded depth has a significant effect on the deformation and earth pressure distribution of the foundation pit. The earth pressure in front of the pile tends to approach the passive earth pressure as the embedment depth decreases, while the earth pressure behind the pile is in between the Rankine active earth pressure and the static soil pressure; the settlement value and settlement range of the surrounding soil are doubled. The pile displacement increases as the maximum displacement point rises. The maximum displacement of the pile body was used as the basis for determining the instability of the foundation pit. The optimum embedded depth is obtained when the depth of embedment of the pile is 0.22 H (H is the excavation depth of the foundation pit).

Microscopic Evolution of Pore Characteristics and Particle Orientation of Granite Residual Soil in One-Dimensional Compression

“…where n is the total number of the microfabric within a SEM image, l i is the length of each vector (i.e., the major axis of the ellipse), and θ i is the direction of each vector (interval 10 °). The magnitude of the resultant vector L was calculated as 4 Geofluids…”

“…RS has abnormal characteristics, having poor physical properties but satisfactory intact strength and stiffness; however, its intact strength decreases appreciably once its microstructures (e.g., cemen-tation bonding) are destroyed upon loading and disturbance; therefore, the behavior of RS in engineering is quite complex when compared with that of SS [3]. With increasing civil engineering projects being constructed in tropical and subtropical regions (e.g., southern China and Singapore) where RS is distributed widely, its peculiar mechanical behavior has become the subject of extensive concern [4][5][6][7][8]. Because of its unique formation process, the deformation mechanism of RS cannot be predicted using empirical evaluation from previous studies on SS, which may bring difficulties to designing and construction in related engineering projects.…”

Numerical Study on the Effect and Mechanism of Supporting Pile Equivalent Calculation Methods in Pile–Anchor Support System

“…Recently, with the continuous development of computer technology, numerical simulation methods have become an important tool to deal with the problem of foundation pits, and they are widely used in foundation pit design and engineering [4][5][6][7][8][9]. Compared with the traditional empirical formula method [10] and physical model method [11], the numerical simulation method can not only establish a complex three-dimensional model and invert the real pit to a certain degree but also carry out the design optimization work, which saves a large amount of money and time.…”