2015 Vol. 29, No. 4

Development and Creation
Design Practice of Deep Foundation Pit Excavation Adjacent to Metro in Soft Soil Area
CAI Jian-tao
2015, 29(4): 163-168,181. doi: 10.3969/j.issn.1007-2993.2015.04.001
Abstract:
Foundation pit of Suzhou's Shin Kong Mitsukoshi project is a typical deep foundation pit in soft soil area,the nearest distance is only 12 meters on the south side with the new metro line interval,and only 6 meters with Times Square Station basement exterior wall The pit has the strict environmental protection request and complicated geological conditions.Simultaneously,the project construction period is very nervous,and less than 20 months from engineering piles completed to the tower cap structure completed,the conventional scheme is difficult to achieve the above requirements.This paper introduces the excavation engineering difficulties,and targeted measures taken-the pit and underground structure partition,steel support axial force servo system,the composite diaphragm wall,isolating confined water with ultra-deep diaphragm wall etc.Through the analysis of the monitoring data,slop monitoring,the subway structure displacement,confined water indicators are within the prescribed values,the construction period of main structure and the smooth operation of Metro line are ensured.
Study on Borehole Shear Test for Soil Shear Strength Parameter Testing
YU Yong-tang, GAO Yuan
2015, 29(4): 169-172,208. doi: 10.3969/j.issn.1007-2993.2015.04.002
Abstract:
The Borehole Shear Test(BST) was introduced as a new in-situ method for determining shear strength parameters of soils.The borehole shear tests are summarized,including the shearing mechanism,test equipment and test data processing method etc.To evaluate the engineering applicability of the test,the Iowa borehole shear tester are adopted to determine shear strength parameters of unsaturated loess and saturated loess in geotechnical investigation.The test results show that,the BST is a rapid and direct method of measuring the in,situ shear strength of loess,and gains a good linear relativity between normal stress and shear stress.Then in view of existence question in BST,the recommendations for future research are also proposed.
Field Test and Numerical Simulation of Soft Soil Foundation Strengthened by Vacuum Preloading
YAN Li-ming, LIU Xiao-yong, LIU Bao-shi
2015, 29(4): 173-178. doi: 10.3969/j.issn.1007-2993.2015.04.003
Abstract:
This paper conducted field test based on a soft soil foundation reinforcement project by vacuum preloading method in Wenzhou,and the variation rule of surface settlement,horizontal displacement,vacuum degree and pore-pressure were monitored and studied in the process of vacuum preloading.Then,a finite element calculation in ABAQUS software has been performed to simulate the field test with plane strain model.The reliability and applicability of the numerical model was verified by comparison of the simulation and the corresponding results,it could be applied in the design and numerical calculation of similar vacuum preloading projects.
Experimental Research and Application of New Method of Stable-grout-based Rock Grouting
ZHENG Yu-hui
2015, 29(4): 179-181. doi: 10.3969/j.issn.1007-2993.2015.04.004
Abstract:
For a long time,cement grouting has been one of the key foundation treatment methods in hydropower project.In conventional grouting,full-length-hole single-stage or multiple-staged grouting method is generally adopted,in which grouting pressure is determined as per the depth of grouting sections and geological conditions,and grout mixture used changes gradually from thin to thick.Many problems are found while reviewing traditional grouting method,especially the problems of grout mixtures.New-type stable-grout is researched and proposed in this paper by targeting grout problems of conventional grouting method.This stable grout is practically applied with the adoption of the new method in certain hydropower project and success there of has been proved in practice.
Automatic Monitoring of Large Caliber Sewage Duct Pipe Jacking Engineering Crossing Expressway
DONG Jun-zhao, PENG Zhong
2015, 29(4): 182-186. doi: 10.3969/j.issn.1007-2993.2015.04.005
Abstract:
In the heavy traffic,highway traffic big car settlement monitoring,such as carried out by the traditional manual method,will bring a lot of inconvenience to the layout and measurement work.This paper automatic monitoring through the process of pipe jacking crossing expressway,and collection,analysis and research on the related monitoring data,provide the basis for the design and construction of the relevant follow-up project,promoted the development of monitoring information technology industry.For the future monitoring of similar engineering has a very good reference.
Technology Probe and Research
Case Study for the Influence of Uplift Pile Arrangement Type on the Internal Forces of the Foundation
LUO Xiao-dong, ZHANG Huai-jing, SUN Hong-wei
2015, 29(4): 187-191. doi: 10.3969/j.issn.1007-2993.2015.04.006
Abstract:
In order to ensure the safety and normal use of buildings,the uplift pile should be used when the underground water level is high.By using MIDAS/GTS to calculate the foundation slab and beam bending moment of three normal uplift pilearrangement type in actual projects at different underground water level,the best type for certain working condition could be found.
Application of Strength Reduction Method in Reinforced Soil Slopes
XU Ya-qi, ZHU Qi-kun
2015, 29(4): 192-196. doi: 10.3969/j.issn.1007-2993.2015.04.007
Abstract:
In the slope stability analysis,the limit equilibrium method and strength reduction method have been widely applied;Compared with limit equilibrium method,strength reduction method not only can get the safety factor of the slope,but also the soil plastic strain,stress and displacement;However,it cannot be used to calculate the reinforced soil ideality.In this paper,through the analysis of reinforced soil reinforcement mechanism,regard the reinforced soil as a whole according to the equivalent stress method,using a new cohesion to replace the original soil cohesion,so as to realize the strength reduction method.Take a high fill slope in Shanxi as an example,it adjusts the equivalent cohesion of reinforced soil using the result from safety coefficient of limit equilibrium method,then comparative analysis the equivalent cohesion in different height slope,finding out that the slope height will have influence on the increment of cohesion,the higher of slope,the greater of the increment cohesion.The results of finite element method can be used to optimize the design of slope,and to provide a way for research reinforced soil.
Application of Improved Expansive Soil in the Hebeng High-speed Rail Roadbed Filling
XU She-hui
2015, 29(4): 197-200. doi: 10.3969/j.issn.1007-2993.2015.04.008
Abstract:
The engineering properties of the Hebeng high-speed rail are analyzed.Free expansion rate,grain composition test index is obtained through the indoortest of typical soil samples.Different lime-doped rates test of several typical soil sample were conducted.Reasonable lime-doped rates of Hebeng high-speed rail expansive soil is determined according to the strength and swell-shrink and rational water index.
The Introduction of ASTM D2487 for Classification of Soil
HE Ping
2015, 29(4): 201-204,217. doi: 10.3969/j.issn.1007-2993.2015.04.009
Abstract:
This paper introduces the soil classification and naming rules in ASTM D2487-00.Comparison from grain grade,naming and code are given beteween ASTM D2487-00 and GB/T 50145-2007,some conclusions are drawn to provide references for the related applications.
Explore the Road Collapse of Shipyard Using Geophysical Technology
WU Yue-yuan, LUO Jia-rong
2015, 29(4): 205-208. doi: 10.3969/j.issn.1007-2993.2015.04.010
Abstract:
The ground near the east of harbor was found collapse phenomenon in a shipyard of Shanghai.By surveying the surrounding environment and understanding the source of surface water,we used the corresponding geophysical technology to explore the road collapse of shipyard.It can help us to determine the scope of collapse and the depth of collapse.By analyzing the cause of formation,it can eliminate the hidden dangers of safety production for shipyard.
Analysis of Multistage Building Slope Treatment Project in Slippery Stratum
LI Yang-qiu, LI An-xing, TANG Qiu-yuan
2015, 29(4): 209-213. doi: 10.3969/j.issn.1007-2993.2015.04.011
Abstract:
The project is located in the first level slop of Yangtze River and belongs to the slippery stratum.There had been adverse geologic phenomena like landslide and deformable body near it.After cutting slopes according to the construction scheme,the tableland is divided into three relatively high artificial slopes,and the high-rise buildings are located in each plain stage of all stages of side slopes and near to the slope top.After the construction of buildings is finished,under the influence of earthquakes,wind loads and vertical loads,there will be part of the horizontal force transmitted to the retaining structures through rock and earth mass of slopes,resulting in a increase of the surplus sliding force on retaining structures.Through combing theoretical formulas and numerical simulation method,this paper checks the overall stability of the slope and the local stability of artificial side slope,confirms the rationality of retaining scheme,analyzes the trend of architecture horizontal load's influence on the internal force of side slope retaining structure,proposes that the retaining structures should be designed to consider the adverse effects of building transmitting horizontal force and recommends to take measures such as strengthening the construction side piles,strengthening the rigidity of ground beams and additional tensile anchor on pile block to enhance the capacity of building itself to resist part of horizontal force.
Research of the City Common Information Query System Base on ComGIS
ZHOU Mi, ZHOU Yuan, LIN Dong-wei
2015, 29(4): 214-217. doi: 10.3969/j.issn.1007-2993.2015.04.012
Abstract:
ComGIS is the new generation of geographic information system that adapts the software module tidal.In order to improve efficiency and quality in developing GIS software and reduce the nonessential repetition work,it is necessary to develop the GIS system adopting component technology.This paper use Supermap Objects of Supermap Company to develop the common information query system of Xuzhou.The paper starts from component technology and describes the development model of component-based GIS software development method by combining component technology with GIS technology.The common information query system of Xuzhou can not only achieve an electronic map browser,as information inquiries and other basic functions,but also for the special analysis.It can provide the useful information for the users.