Papers by Author: Guang Hua Yang

Abstract: The rubble mound seawall to be discussed is built on the silted floor of the Pearl River estuary. To meet the requirements of wave defending, stability and anti-seepage, foundation replacement method was used to enhance its groundsill and geomembrane was laid on the downstream slope for seepage control. However, because the silted floor in the foundation wasnt totally removed in the construction process, settlement deformation occured and the downstream slopes trended to slide down. Furthermore, due to the insufficient back pressure for seepage control, serious leakages and piping appeared on the anti-seepage body. The water leakage phenomenon showed little improvement even after additional cement grouting and plastering on the slope. In this paper, a seepage pressure stick slope reinforcement scheme is proposed to handle this problem. After the reinforcement, the water leakage has been prevented and the safety factors of the seepage and slope meets the safety requirements. The pollution caused by the seepage is also eliminated. The proposed technique can give a good reference to the other seawall reinforcement problems.

Abstract: A finite element model considering the high-speed train excitation loads, track structure, vibration reduction measures, station structure, characteristics of foundation soils was established to study the problem of vibration in the underground Futian hub of Guangzhou-Shenzhen- Hong Kong high-speed rail. The first 200 natural frequencies of the station are all within 40Hz, the vibration energy concentrates mainly in the second and third floors, in the form of bending vibration mode; the modes of local orbital plate mainly accounts for vertical vibration, and the lowest frequency is near 26Hz.The additional displacement and stress induced by vibration is not great in general, vibration energy of the structure is mainly concentrated in the band of 15~20Hz. When the train passes by at a speed of 200km/h, without damping rubber pads, the maximum vibration level at upper floors is 57.9 dB, while with damping pads under the orbits the vibration level decreases by 5~6dB,which is a significant effect.

Abstract: At present, foundation bearing capacity used in the practical engineering design is often based on controlling strength, if such it may produce some problems, even accidents. In this article, using Midas-GTS and FLAC3D software to analyse a simplified example of a problematic engineering, we obtain the result that under the conditions of enough strength; the whole structure generates a lot of uneven settlement. On this basis, it explains that the lack of bearing capacity of foundation ideology. And we proposed explicitly foundation bearing capacity should include deformation, in hopes that the influence on the later engineering.

Abstract: Choosing an accurate soil model is the key point in calculating the foundation settlement. The commonly used models in engineering practices are the Winkler’s model, elastic half space model and finite compressible layer model. Among these models, the finite compressible layer model is widely used in the designing of raft foundation. As the finite compressible layer model can not reflect the nature of the in situ soil and the nonlinear settlement, in this paper we try to modify the elastic modulus E by the secant modulus in order to improve the soil model of finite compressible layer.

Abstract: At present, in the deep soft soil area, pile types of composite foundation include rigid-flexible and long-short piles, rigid long- short pile , pile partner, and this paper proposes a new type of pile - rigid long-short piles with no cushion short pile. Using the one Finite element software Midas- GTS , this paper compared these pile types ,in vertical direction element stress, pile-soil stress ratio and cushion stress level the cushion of pile-soil stress ratio and stress level, to illustrate the advantages of the new pile.