Li Y.,Hubei Engineering University |
Yi H.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Wu J.,XiAn Changqing Technology Engineering Co. |
Xu L.,Hubei Engineering University
Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia | Year: 2016
The use of recycled concrete has become an important means to solve the waste concrete in order to reduce pollution and save resources. This paper uses the gray relational model to analyze the experimental data of recycled concrete. Based on sensitivity analysis of replacement ratio of recycled coarse aggregate, admixture, water-binder ratio, cement, fine aggregate and coarse aggregate, the sensitivity of each influencing factor on the strength of recycled concrete is obtained. Cement, coarse aggregate, fine aggregate and water-binder ratio have significant effect, and the correlation coefficient is 0.75-0.84. The influence of the replacement ratio of recycled coarse aggregate, aggregate grade and admixture is moderate, compared to the above factors, and the correlation coefficient is 0.64-0.69. However, aggregate type is the least influence with correlation coefficient 0.46. According to the sensitivity analysis, the suggestions for the strength of recycled concrete are put forward. Hope to provide reference for the follow-up study.
Yang G.-H.,China Institute of Water Resources and Hydropower Research |
Yang G.-H.,Wuhan University |
Luo Y.-D.,Wuhan University |
Luo Y.-D.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2013
Foundation settlement calculation has been a hot and difficult problem in geotechnical engineering study. The difficulty lies in large differences between the geotechnical parameters of indoor tests and in-situ tests. Especially for the sand foundation and hard clay foundation with high structural strength, there is a large error between calculated settlement based on the laboratory test parameters and the actual one. The tangent modulus method based on the in-situ plate loading tests to determine the calculation parameters can overcome this shortcoming and reflect the non-linearity of foundation settlement, which is a new progress of foundation settlement calculation. However, compared with other tests, the in-situ plate loading tests have more difficulties, and it is also difficult to reflect the characteristics of deep soils. By using the systematic geotechnical test data by Riverside Campus, Texas A & M University, United States, the feasibility of the tangent modulus method for calculating the nonlinear settlement of sand foundation is examined, and then the tangent modulus method by adopting lateral pressure tests and static cone penetration tests to determine different soil layers is studied and lastly the results of loading tests on different plate sizes are verified. The results show that the calculated parameters needed in the tangent modulus method determined by the lateral pressure tests and static cone penetration tests are feasible. In addition, when they are used in the tangent modulus method to calculate the load experimental curves of different plate sizes, the calculated nonlinear curves have good consistency with experimental ones. This method is a simple and easier access to deep soil parameters, providing an easier way of the determination of the parameters of the tangent modulus method. It is of great significance in solving problems of foundation settlement calculation and in promoting the development of the design theory of the foundations.
Li A.G.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Li A.G.,University of Hong Kong |
Tham L.G.,University of Hong Kong |
Wen J.P.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Chen S.C.,Shenzhen Land Investment and Development Center
Geotechnical Special Publication | Year: 2014
This paper mainly introduces the design and construction of ground improvement inthe Qianhai reclamation area, Qianhai Bay, Shenzhen, China. The seabed water level in the reclamation area is about 2.0 to 3.0 m, the thickness of the soft soil ranges from 6.0 to 15.0 m, and the treated reclamation area is about 7.62 km2. Different soft ground improvement methods were adopted to treat the marine soft soil and backfilled soil to satisfy the requirements of various development purposes, such as: (1) explosion method for the sea embankment construction; (2) riprapping used to strengthen dikes; (3) fill-surcharge preloading and vacuum-surcharge preloading used to treat the soft clayey soils, dynamic compaction, vibro-stone (sand) columns, deep cement mixing; and, (4) also used to treat road foundation soils. The features, advantages and limitations of these methods are discussed in the paper. © ASCE 2014.
Xu X.-C.,CAS Wuhan Institute of Rock and Soil Mechanics |
Zhou W.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Chen S.-X.,CAS Wuhan Institute of Rock and Soil Mechanics
Yantu Lixue/Rock and Soil Mechanics | Year: 2015
Environmental temperature is one of the external factors that influence the cracking of expansive soil; and initial water content and dry density are the important internal factors. In order to study the cracking characteristics and influencing factors for expansive soil, the tests of cracking process are conducted on remolded Nanyang expansive soil with different initial water contents and different initial dry densities. The results indicate that cracking process can be divided into three phases, i.e. soil shrinkage-crack generation, rapid crack expansion and stabilization. The ratio between shrinkage area plus crack area and initial area is defined as fissure ratio, which can describe not only the drying shrinkage characteristics but also the cracking characteristics, and is suitable for depicting the crack propagation process of small size sample. Temperature has a certain extent influence on the dehydration process of expansive soil; a higher temperature can result in a small fissures ratio. Initial water content is positively related to cracking degree. Initial dry density has a negative correlation with cracking degree. ©, 2015, Science Press. All right reserved.
Luo Y.-D.,Wuhan University |
Luo Y.-D.,Shenzhen Geotechnical Investigation and Surveying Institute Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2011
Compacted soil, which widely exists in many sorts of engineering projects, is commonly unsaturated soil; and its physico-mechanical characteristics are influenced by soil moisture. Because of the difficulty in matric suction measurement, it is hard to apply the unsaturated soil strength theory to compacted soil projects. This paper aims to research how much influence on shear strength of compacted soil when soil moisture varies, and tries to find an easy and useful way in determining the shear strength of unsaturated compacted soils. Research works start from the theory of unsaturated soil, and the mechanism, with which soil moisture affects shear strength of compacted soil, is analyzed. Triaxial shear test results of five sorts of unsaturated compacted soils are rearranged and analyzed; and strength parameters of direct shear test are collected and arranged from data of some filled and compacted soil projects. Analysis shows that matric suction contributes a considerable portion of shear strength in the compacted soils; and the influence of soil moisture on shear strength of compacted soil is obvious and can not be neglected. A fine linear relationship between logarithmic saturation and cohesion of compacted soil is found in project data; and a simple method for calculating shear strength of compacted soil, which can take saturation degree influence into account, is presented.
Hu C.,Wuhan University |
Yan X.,Shen Zhen Geotechnical Investigation and Surveying Institute Co.
Proceedings of 4th International Workshop on Advanced Computational Intelligence, IWACI 2011 | Year: 2011
Effective mining technology can extract the spatial distribution pattern of the road network traffic flow. In this paper, the similarities between traffic flow objects with spatial temporal characteristics were measured by introducing the Dynamic Time Warping (DTW) and the shortest path analysis method. We proposed a kind of clustering analysis method for road network traffic flow data. So that traffic flow data objects with similar properties and space correlation are clustered into one class, which found that the spatial distribution pattern of road traffic flow. The experimental results show that the method was effective. The road network was classified reasonably, and classification results could provide traffic zone division with decision auxiliary support. © 2011 IEEE.
Qiu J.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Gao W.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Zhou Z.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Liu B.,China University of Mining and Technology |
And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2012
In the construction of the extra-deep foundation pit of Shenzhen Ping'an Financial Center, the maximum excavated depth is over 30 m and the minimum distance to metro structures is just 5.3 m. Some of the super-large digging piles will be constructed subsequently with the top opening diameter of 9.5 m. The maximum depth for piles construction is 68 m below the ground surface. Therefore, it is key to consider and control the settlement of metro structures during the pile construction. Based on the actual construction conditions, the three-dimensional numerical simulation method was used for analysis of digging piles construction. Hereby, a series of significant countermeasures were proposed and performed before pile constructions to reduce the excessive settlement, such as high-pressure jet grouting and curtain grouting according to geological conditions. The settlement values monitored increased slightly and matched well with the predicted results after the completion of digging piles, which indicates a better controlling of metro structure deformation contributed by the effective countermeasures.
Zhang A.,South China University of Technology |
Zhang A.,Shenzhen Government Investment Project Evaluation Center |
Mo H.,South China University of Technology |
Li A.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013
Foundation pit excavation in the building compact district of urban will absolutely induce soil lateral movement, which may generate the additional deflections and bending moments in the adjacent pile shaft, and may lead to their superstructures distress, even failure. To avoid the drawbacks of three-dimensional numerical analysis, such as complexity modeling and time consuming, the two-stage method(TSM) is presented for determining the behavior of adjacent pile caused by foundation pit excavation. Firstly, the additional lateral displacement of soil mass due to adjacent foundation pit excavation is calculated by the virtual image technique. Secondly, the governing differential equations are built up based on Winkler model and their analytical solution of matrix is derived. Finally, analysis of case histories show that the calculated results of analytical solution are reasonable and could be used to analyze the influence of excavation on adjacent pile foundations.
Zhou Z.-L.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Fu Y.-B.,Shenzhen University |
Qiu J.-J.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Zhao J.,Shenzhen University |
He C.,Shenzhen Parkland Real Estate Development Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2014
For the deep foundation pit in soft soil areas of coastal reclamation, the composite supporting structure, which is combined by row piles, upper inner support and the lower anchor is analyzed. The mechanical behaviour of the support system is optimized by the upper inner support with more stiffness. The space of pile foundation construction is provided and the interaction between support and basement construction is reduced by the lower anchor. Preliminary studies on interaction between support and anchor are made by analyzing the field monitoring and numerical simulation. The composite supporting structure is convenient in building and has advantage of cost in soft soils, and it may provide valuable references for similar projects in the future.
Zhang K.-C.,Shenzhen Geotechnical Investigation and Surveying Institute Co. |
Li J.-M.,Shenzhen Geotechnical Investigation and Surveying Institute Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010
The foundation pit collapse of Xianghu Station of Hangzhou metro is a major liability accident. Based on the analysis of the accident investigation by the technical team, further analysis of stability of deep foundation pit is made by the authors. The following conclusions are drawn: the underground diaphragm walls do not penetrate the soft clay, and the soft clay is not treated, causing the wall subsidence. The uplift-resistant stability and kick-resistant stability are analyzed by use of different parameters of shear strength and different standards. They can not meet the requirements. This may be the indirect potential causes of the accident. It should be worthy of attention for similar projects in the future.