2007 Vol. 21, No. 2

Display Method:
Evaluation on the Effect of Dynamic Compaction Based on Multistage Fuzzy Synthetic Judgment
Tu Qiliang
2007, 21(2): 55-59.
Abstract:
There are many indexes for testing the dynamic compaction effect of lager-scale engineering which cause great difficulties for the comprehension evaluation of the effect. Based on the single factor evaluation and the rationalization of the weights for various factors, a multistage model for fuzzy comprehensive evaluation is set up for the dynamic compaction effect evaluation of the dredger fill. The result is scientific and reasonable. The method has the advantages of low cost, easy application with remarkable effect in short construction period, and it may be a reference for the design and field evaluation of harbor, embankment and airport runway.
Experimental Study on the Micro Failure Mechanism of Jinchuan Soft Rock
Wang Weiwei, Cao Ping
2007, 21(2): 60-63.
Abstract:
Jinchuan ore-rock failure surface micro test is carried out under creep states to study the micro failure character and its mechanism. Based on the test and study, the mechanism of the creep of Jinchuan ore-rock is obtained. The micro failure mechanism of Jinchuan Mine soft rock is brittle fracture under the condition of the comprehensive effect of stretch and shear action. Based on the research of microcosmic creep morphology, the relationship between the creep evaluation process and the micro fracture appearance characteristic, the creak nucleation, the creak propagation and the fracture way is revealed.
Experimental Research on Static Earth Pressure Coefficient Distribution Rule of Deep Soil
Xu Zhiwei, Zhou Guoqing, Zhao Xiaodong
2007, 21(2): 64-66.
Abstract:
One of the theoretical and technical puzzle of deep coal mine design and construction is the computation and prediction of static earth pressure. The present high pressure experimental research and analysis of undisturbed deep soil indicate that the static earth pressure of thick overburden is considerable different from that of superficial soil. It is necessary for deep coal mine design and construction to consider this particularity of earth pressure so as to avoid engineering accident and heavy lose of lives and property.
Design and Static Load Test of Improved Pile Tip Soil
Zhang Lianhua, Luo Kang
2007, 21(2): 67-69,85.
Abstract:
The design of composite subgrade treated with jet grouting is introduced and some beating capacity testing problems of pile tip soil treated with jet grouting is presented. There are common grounds and diversities of bearing capacity tests of comtposite subgrade and pile tip treated soil. A combination static load test method is put forward. The practice proves the effectiveness of the method in engineering project.
Discussion on Testing Soil Compactness by Rayleigh Wave Exploration
Yang Tianchun, Xiao Qiaoling
2007, 21(2): 70-73.
Abstract:
There is a nonlinear relationship between the velocities of Rayleigh and the compactness of soil in Rayleigh wave exploration. So, nonlinear inverse method is employed to obtain the compactness date based on the Rayleigh velocities. An artificial neural network is adapted to inverse the compactness instead of the regression analysis method. According to the comparison between the artificial neural network results and the result of impregnation sand method's at the same condition, the mean absolute error is 1. 188 6%, and the average relative error is 1. 221 4%. It illustrates that the artificial neural network method is feasible in compactness reversion, and its precision is higher than the regression analysis method.
Research on Building Process Control of the Impact Imitating Test Bed of Spaceflight's Return Capsule Landing
Peng Youjun, Jin Huai
2007, 21(2): 74-77.
Abstract:
Based on the earth quality condition and basic method of geotechnical engineering, an impact imitating test bed of the spaceflight reture capsule is built. The material quality, parameter of construction technology and construction method is strict controlled in this building process which adopts field test data such as light dynamic penetration test, water content and dry density and little diameter load board experiment. According to thee methods, it can appraise the quality situation of testing bed in time, and realize informative control construction. Then the build quality of the bed is guaranteed. This research has an important meaning in science and technology field of our country national defenee.
Analysis on the Land Subsidence Induced by City Construction
Jie Yuxin, Gao Yan, Li Guangxin
2007, 21(2): 78-82.
Abstract:
After land subsidence by exploiting ground water being controlled, the subsidence induced by city construction became more and more obvious. It is found that the engineering-related subsidence increased with the construction scale and speed. Bigger building density and bigger volumetric fraction caused bigger subsidence. The paper involved analyzing the macro effect of loads distributed with certain space, proposing the concept of equivalent effecting load, discussing the relationship between city building and large-scale equivalent effecting load, and interpreting the construction-induced land subsidence in shanghai. It is thought to be helpful for urban planning in cities with soft subsoil.
Direct Calculation Method for Cross-section Design of Retaining Wall
Yuan Jian, Huang Taihua
2007, 21(2): 83-85.
Abstract:
Based on meeting the requirement of ground bearing capacity, the allowable range expression of anti-overturning safety factor is derived. The relative parameters are expressed with base width and the relation graphs of conversion factor are presented, and then the cross-section of retaining wall is designed directly by combining the stability requirement of anti-sliding. The calculated result shows that this method makes the design simple and reliable. It may be a reference for engineers.
Study on Subgrade Reacting Force Distribution Rule of Sluice With Tenons Under the Foundation Mat
Tao Mingxing, Cao Guofu, He Zailiang
2007, 21(2): 86-88,100.
Abstract:
The subgrade reacting force in different stages through construction pericd is measured by in-site testing of a real sluice with tenons under the foundation mat, the corresponding subgrade reacting force is worked out by FEM(finite dement method). By comparing and analysing of the observed value and computational results, it is found that the subgrade reacting force is nonuniform and concentrated under the tenons. With the increasing of the lead from upper, subgrade reacting force inclines to be uniform.
Study on the Method of Sand Liquefaction Evaluation
Lin Huaguo, Jia Zhaohong, Zhang Lili
2007, 21(2): 89-93.
Abstract:
Sand liquefaction evaluation plays important role in seismic investigation and design of building. Based on the contrast between the most frequent methods in the evaluation of liquefaction, such as the method recommended in code for seismic design of building(GB50011-2001) and Seed method, a new method for evaluation liquefaction is deduced. The method possesses many preferred qualities, such as its accurate result, the reasonable and simple process of calculation and the close relation with engineering. Extensive application is advisable.
Summarization of Urban Mixed Fill Foundation Treatment in Beijing
Zhou Junhong, Cao Liang, Ma Hongjian
2007, 21(2): 94-100.
Abstract:
A lot of mixed backfill foundation exist in Beijing city mostly because of the excavation of sand. The composition of this kind of foundation is complex, including structural garbage, industrial garbage and living garbage. The optimal ground treatment methods must be adopted in this kind of foundation for its difference of thickness, negative friction, remarkable difference of uniformity, low bearing capacity, high compressibility, high indeterminacy and nothing of regularity. This kind of foundation is usefull in the buildings only after ground treatment. Taking Beijing Pearl River Luxury Apartment as an example, the component type foundation treatment of Beijing urban mixed fill is dissertated. The effect of the treatment is analyzed by the test and the data of settlement in high-rise building. The elementary conclusion is educed.
Characteristic Analysis of Xujiadong Ancient Landslide Reactivation and Optimization of Its Control Design Scheme
Peng Yuansheng, Zhang Keneng, Yang Chuande
2007, 21(2): 101-104.
Abstract:
Based on the analysis of geomorphologic features, site investigation of old-aged landslide features, geological environmental conditions for landslide developing and deformation monitoring to the landslide, Xujiadong slope is congnized to be an old-aged landslide. Optimum design is presented on the basis of the analysis of the slip soil shear strength characteristic and sensitivity of slope stability to underground water level. It is applied in engineering practice, and improve both the reducing engineering cost and the insuring purpose of landslide correction, can be a reference for the other landslide investigation and correction.
Practice of Geological Investigation For Landslide Stabilization——With Dayu Village Landslide in Yuyao City of Zhejiang Province For Example
Chen Xiuqing, Huang Xiaohui
2007, 21(2): 105-109.
Abstract:
Based on the investigation means and the analysis of the geological condition of Dayu village landslide, the cause and mechanism of the formation and the developing trend is studied, and the stabilization and the damage degree is evaluated. The general procedure and content of the landslide geological hazards is elaborated, and it can be used as a reference for similar engineering.