Jiang Xu

Southeast University (China) | SEU · civil engineering

This paper proposes a cyclic strain wedge finite element strip model to analyze of the cyclic bearing characteristics of pile foundation. First, the strain wedge body is meshed by every soil element, which can assign the stress-strain relationship to each soil element of the wedge body. Then, the equivalent substitution stress‒strain relationship o...

With the development of society and the economy, the scale of underground cavern engineering is becoming increasingly larger. Unfortunately, underground cavern disasters such as roof collapse and rockburst occur frequently. Many studies have shown that the collapse of underground caverns is closely related to joints, which restricts the development...

As the relative displacement of the pile-rock interface increases, the sliding and mutual squeezing between asperities of the pile-rock interface causes the normal stress increases by Δσn with the normal displacement. All prevalent theoretical methods use the elastic solution of cylindrical cavity expansion in an infinite medium to calculate the no...

Shaft resistance generally dominates at the service loads of rock-socketed piles and therefore is always a topic of large research interest. This paper reviews the research progress that has been made in the last four decades in understanding the shear mechanism of the pile–rock interface and in calculating the shaft resistance. First, particular a...

Field load tests were conducted for three large-diameter drilled shafts in the flood detention area of the grand bridge project of Beijing–Hangzhou Canal. Bi-directional testing of two grouted drilled shafts (TS1 and TS2) and one ungrouted drilled shaft (TS3) was used to study how post-grouting improved the bearing capacity of the drilled shafts. B...

This paper presents an analytical solution for the resistance of saturated soil to a laterally vibrating pile. Based on Biot's model for fluid-saturated porous media, by setting the dynamic vertical normal stress in the soil equal to zero and combining the Helmholtz decomposition scheme, a closed-form solution is obtained for the resistance of the...

Nondestructive imaging techniques enable the study of failure mechanisms within physical models for a wide range of geotechnical problems. This paper presented an innovative experiment that utilized micro X-ray computed tomography (CT) and an in-house experimental apparatus to study the bearing mechanisms of model piles embedded in synthetic soft s...

Data from 187 loading tests on rock-socketed shafts are used to develop a new relationship between the ultimate shaft resistance f su and unconfined compressive strength σ c of intact rock. The adhesion factor α q of the shaft resistance for different types of rock and the relationship between α q and the embedment ratio are discussed. Furthermore,...

Coalbed methane (CBM) development is in progress in northwestern China, where there are deposits of medium volatile bituminous coal (MVBC) and high volatile bituminous coal (HVBC). Stress sensitivity can lead to low gas-production during CBM development. In this study, three groups of HVBC samples and one group of MVBC samples are applied for low-f...