2016 Vol. 30, No. 2

The 7th National Geotechnical Engineering Communication Meeting Special Report
Nondestructive Detection of Ground Defects and Risk Evaluation for Safety Evaluation of City Roads
Xiao Min, Shen Xiaoke, Jia Hui, Su Zhaofeng, Chen Changyan, Bai Chaoxu
2016, 30(2): 55-62,84. doi: 10.3969/j.issn.1007-2993.2016.02.001
Abstract:
Ground-defects-induced road surface collapses have increasingly taken place in recent years and thus it has become a demanding need and a conundrum as well to detect the distribution and prevent disastrous impact of the defects induced mainly by unfavorable ground conditions for the safety of city road systems. By far the development of the ground defect detecting industry has been hindered due to lack of a classification system of the ground defects, relevant code(s) of practice and criteria of risk evaluation. Based upon the studies and practical applications of the studying outcomes of BGI Engineering Consultants in the last decade, applications of commonly used detecting techniques and evaluation of related risks are reviewed in this paper.
Development and Creation
Geotechnical Investigation Field Data Collection System Based on Tablet PC
Liu Wenbin, Guo Zhongze, Yan Degang
2016, 30(2): 63-65,99. doi: 10.3969/j.issn.1007-2993.2016.02.002
Abstract:
In the information age, internet and database technologies are developed rapidly, while the development of geotechnical investigation is lagging far behind the times because the field data is still being recorded by paper and pen. In this article, Geotechnical Investigation Field Data Collection System was designed and developed in Java language based on deep analysis of work flow and characteristics of field operation. C/S and B/S framework were adopted in this system, all of the filed data of stratum, in-situ test, sampling and underground water, can be recorded and transferred in real time on the client side, and much work can be finished on the server side, such as task creation and dispatch, record generation, soil layer classification, data output and so on. By using the collection system, data input can be simplified, numerical data about investigation can be output directly, the big database about investigation can be created and more application can be developed easily. It is hoped that this article may provide beneficial reference for drilling informatization by primary exploration and research of the geotechnical investigation collection system.
Reinforcement Design of Counterfort Retaining Wall for Embankment Slope of Mountain Areas
Zhang Liang
2016, 30(2): 66-69,77. doi: 10.3969/j.issn.1007-2993.2016.02.003
Abstract:
This paper based on geological conditions, soil parameters, design parameters of counterfort retaining wall and feedback information of construction, analyzed the inclination accident of a road counterfort retaining wall located in Chongqing. According to the analysis of the result and deformation characteristics of counterfort retaining wall, analyzed the cause of counterfort retaining wall inclination. Finally, the foundation grouting reinforcement treatment and the precaution using prestressed anchorage to strengthen the stability of counterfort retaining wall is put forward.
Design and Application of the Foundation Pit Deformation Monitoring Integration of 3D Data Acquisition and Processing System
Sun Yuanping, Yao Peijun, Liu Hongchen
2016, 30(2): 70-73. doi: 10.3969/j.issn.1007-2993.2016.02.004
Abstract:
Introducing the use of Visual C++ combined with the deformation monitoring of the foundation pit excavation, making the foundation pit deformation monitoring integration of 3D data acquisition and processing system, it realizes: project management, data transmission, data sorting, adjustment file generation, adjustment software call each other, the restilt of adjustment output, results fable and results of curve generation, data analysis and deformation prediction function.
Measurement for Soil Deformation During the Diaphragm Wall Trench Construction
Yan Ronghua, Du Mingli, Zhu Ming
2016, 30(2): 74-77. doi: 10.3969/j.issn.1007-2993.2016.02.005
Abstract:
In order to analyze the influence of soil deformation surrounding the trench of diaphragm wall during the construction period, the diaphragm wall trench, thickness 1.2 m, width 4. 5 m and depth 61.0 m, was tested before the retaining wall of foundation pit constructed in Nanjing Hexi area. The results show that soil deformation in different depths appeared different displacement degrees when the trench was excavated, and part data of monitoring were negative The soil deformation surrounding the trench had a little impact on the environment, when the single trench of the diaphragm wall was constructed.
Evaluating Coefficient of Subgrade Reaction by Statically Tests and Its Application
Zhang Wu, Zhang Bo, Zhang Shaoqin
2016, 30(2): 78-84. doi: 10.3969/j.issn.1007-2993.2016.02.006
Abstract:
This paper puts forward the methods of calculating modulus of subgrade reaction, based on static loading test which contains full load segments, incomplete, irregular, or lack of clear ultimate load curves. According to static load tests instance in 4 project testing in African continent, the modulus of subgrade reaction on silty sand soil, gravelly soil, testing result based on static loading test is higher than curve fitting, and lower than existing literature. The modulus of subgrade reaction has bigger influence on infrastructure character analysis, get modulus of subgrade reaction from static loading test was important in the actual projects.
Application of BIM Technology in Geotechnical Engineering-Taking the Foundation Pit Engineering of Wuhan Asian Hospital as an Example
Liu Xu, Liu Zhihao, Lei Zhijuan
2016, 30(2): 85-88. doi: 10.3969/j.issn.1007-2993.2016.02.007
Abstract:
BIM technology has many characteristics, such as 3D visualization, collision detection, engineering information management, it greatly improves the engineering quality and efficiency, in the construction field has got rapid development. However, in geotechnical engineering, because of its charging mechanism, the limitation of the software function and the limitation of the application, the development of geotechnical engineering is seriously lagging behind. With the development of design visualization and information, BIM will also be developed in the geotechnical engineering. In this paper, the development status of BIM is analyzed, and the expectation is prospected. The design of BIM was carried out based on Wuhan Asian heart hospital foundation pit project,model building methods and application methods are discussed, which have a certain guiding significance to the development of BIM in geotechnical engineering.
Technology Probe and Research
Simply Discussion of Several Problem for Construction Monitoring of Foundation Pit Engineering
Yan Boduo, Wang Yuping, Ma Lianzhong
2016, 30(2): 89-93,108. doi: 10.3969/j.issn.1007-2993.2016.02.008
Abstract:
This paper simply describes features of construction monitoring, project design of monitoring, It is includes the contents of monitoring, the layout of benchmarks, the layout and observation of monitoring points, the frequeney of monitoring, and alarming value. As well as precision requirements of monitoring, etc. At the same time, the present problems in monitoring work for foundation pit engineering are simply descriped, as well, the suggestions proposed for reference.
Methods and Engineering Cases of Ground Treatment in Beijing Mountain Areas
Liu Bo, Wei Haitao, Li Liangjie
2016, 30(2): 94-99. doi: 10.3969/j.issn.1007-2993.2016.02.009
Abstract:
Along with the rapid development of economy, building land is less and less, one of the city development di-rection is to fully employ the mountain land. by analyzing the stratigraphic features, main with a typical in Beijing mountain area near struction method were detailed introduced to This aticle summarized the treatment of complicated foundation in mountain area form and major hazard of foundation, previous engineering experience. Combined the slope engineering of foundation treatment cases, design calculation and conprovide a reference for similar projects meanwhile.
The Application of Ground Penetrating Radar Detecting Ground Damage
He Liang
2016, 30(2): 100-104. doi: 10.3969/j.issn.1007-2993.2016.02.010
Abstract:
On the basis of the radar theory, combined with the engineering example, this paper expounds the application of GPR in the detection of foundation pit excavation in the disease. Through the analysis of the mechanism of foundation diseases, summarizes the typical characteristics of the soil foundation diseases such as osteoporosis, image separation and slippage line profile measured in the radar chart and the single waveform, and determine the extent of disease and the spatial position of the foundation, the project also uses the site excavation and penetration test of ground penetrating radar detection results; practice has proved that the ground penetrating radar technology is an effective method for rapid detection of foundation diseases, it is worth to popularize.
A Subway Shield Tunnel Construction Monitoring Technology
Sun Jianchao, Liu Jin
2016, 30(2): 105-108. doi: 10.3969/j.issn.1007-2993.2016.02.011
Abstract:
The subsidence of the ground monitoring and control is the most critical issues in the subway tunnel shield construction. Based on a subway shield tunnel construction monitoring technology as an example, analyzes the monitoring project, method, frequency, alarm, control standard, data processing and feedback, such as technology, discusses the factors influencing the surface settlement of shield construction process and construction control technology. The research results in the process of construction of similar projects in the future construction monitoring and control has a reference value.