岩土工程技术

Research of Hydraulic Medium-Small Rivers in City Construction Surveying and Mapping Technical Method

Jiang Quan

2014, 28(4): 163-167. doi: 10.3969/j.issn.1007-2993.2014.04.001

[Abstract](42) [PDF 5798KB](6)

Abstract:
Combined with specific examples of projects,this paper introduced hydro commonly found in the city and the river in measuring engineering structure building type,investigation and measurement field and the corresponding accuracy index,content choice and mapping representation method,especially explored the technology method of surveying and mapping on it on the basis of field water engineering construction structure of the building size and the complexity,and proposesd the corresponding solution with CAD mapping system.

Study on Applicability of a New Model for Describing Ground Settlement Induced by Foundation Pit Excavation

Wang Qiang, Chen Chunshu

2014, 28(4): 168-171. doi: 10.3969/j.issn.1007-2993.2014.04.002

[Abstract](22) [PDF 1993KB](6)

Abstract:
Ground settlement induced by foundation pit excavation always threatens the safety of the surrounding buildings.Based on lots of measured data analysis,a new mathematical model for describing ground settlement is proposed.The expression of the model including the maximum settlement s_max and settlement range r is given according the analysis of proper ties of the model function.Then the test data from relevant papers is fitted to prove that the model has good applicability for describing the distribution of the settlement.Finally,a contrast is made between this model and decentration distribution.The research results will provide references to predict and control the ground settlement induced by excavation of relevant foundation pits.

Method of the Strain Wedge Model Analysis of the Single Laterally Loaded Diaphragm Wall Foundation

Liu Yunzhong, Dai Guoliang

2014, 28(4): 172-176. doi: 10.3969/j.issn.1007-2993.2014.04.003

[Abstract](31) [PDF 2479KB](4)

Abstract:
The single diaphragm wall is widely used in high rise buildings and bridge projects recently.But most of the studies have focused on experimental and theoretical study of vertical bearing properties and only a little of experimental study on lateral bearing properties is conducted.In this paper,the complex three-dimensional characteristics of the contact between the wall and the soil can be transformed into the parameters required one-dimensional elastic beam,and the internal forces and deformation of the wall can be calculated through the elastic beam.At last,the reasonableness of the algorithm can be verfied through the indoor model test data.It can be provided for similar projects.

Research on Computational Finite Earth Pressure Based on Rankine's Earth Pressure Theory

Zhang Qinxi, Deng Chao, Wang Xiaojie

2014, 28(4): 177-182. doi: 10.3969/j.issn.1007-2993.2014.04.004

[Abstract](50) [PDF 4204KB](11)

Abstract:
In the general study of soil mechanics and retaining walls,the calculation method of earth pressure is often the traditional Rankine's earth pressure and the Kulun's earth pressure theory,which are based on the semi infinite soil assumption.Because of the tense city land,the distance between building and supporting structure is often relatively small,and the role of supporting structure is more and more complex.Not only to keep its stability and economy but also to ensure the safety of ad jacent buildings and facilities in the process of urban development and construction.This paper deduced the calculation method of four kinds of finite earth pressure,we get the results that using the limit equilibrium stress analysis to get the limited soil pressure values are smaller and more economic than the other methods under the same conditions.And the formation and the wall distance under different situations have different characteristics in different algorithms.Considering the special conditions of soil pressure calculation method can make the construction design better.

Analysis and Management of Confined Water Inrush of a Deep Foundation Pit in the Floodplain Area of Nanjing Yangtze River

Che Canhui, Zhang Zhibo, Liu Shi

2014, 28(4): 183-187. doi: 10.3969/j.issn.1007-2993.2014.04.005

[Abstract](46) [PDF 2831KB](15)

Abstract:
In the Nanjing Yangtze river floodplain area,the aquifers with great thickness and abundant groundwater have great influence on the deep foundations pits.Specifically,confined water can easily cause water accidents,such as inrushing and piping.This paper briefly introduces the hydrogeological features of the Yangtze river floodplains area,discusses the formation conditions and the treatment of inrushing and piping,and proposes a simple computation based on the condition of the piping to gauge the depth of the leakage point of the envelope.This method is illustrated with a water bursting accident in a depth of 30 meters foundation pit engineering.

Application of “Integration into the Well Technology” in the Construction of Precipitation

Feng Keming, Ma Jian, Wan Jiahe

2014, 28(4): 188-192,217. doi: 10.3969/j.issn.1007-2993.2014.04.006

[Abstract](40) [PDF 10874KB](6)

Abstract:
West Beijing gravel stratum impact drilling technology is often used as well,along with large mechanical volume,long time into the hole,poor flushing quality,much impact on ground transportation,large impact on the environment from mud of the well."Well integrated into the technology" is introduced in this article.With the use of pneumatic Downhole Hammer drilling,it can follow up steel tube wells once well.This construction method has a high aperture efficiency,without preparation of mud,without special wash well,construction area of small,flexible features,especially in improving the environment and transport obvious advantages.This paper describes the application of the process of precipitation in Beijing subway project,discusses a comprehensive set of integrated technologies into the well,after nearly two years of construction practice,fully demonstrated the value of having an excellent reference for similar projects.

Study on Deformation and Failure Characteristics Caused by Stepping Excavation of High Rock Slope

Liu Faxiang, He Peng, Tang Shenggui

2014, 28(4): 193-197,204. doi: 10.3969/j.issn.1007-2993.2014.04.007

[Abstract](27) [PDF 9099KB](9)

Abstract:
Based on field investigation results of high rock slope,rock mass structure characteristics and the main geological factors affecting stability of rock slope are analyzed.According to deformation and failure characteristics of natural rock slope,qualitative analysis prediction for macroscopic deformation characteristics and the failure model occurring during excavating rock slope are done.By the FLAC^3D software based on the finite difference principle and the geological model of left abut ment slope,a numerical model of left abutment slope is established and stepping process of excavating is carried out by the FLAC^3D software as a numerical method.This research obtained the changing law of stress and strain and deformation and failure characteristics of rock mass during various excavating stages of engineering slopes.The achievements from this research had guided stepping excavation of left abutment of Miaojiaba hydropower station successfully.

Discussion on Several Problems of Negative Skin Friction of Pile Foundation

Cai Hongwei

2014, 28(4): 198-200. doi: 10.3969/j.issn.1007-2993.2014.04.008

[Abstract](34) [PDF 710KB](11)

Abstract:
The problem of negative skin friction (NSF) has not been totally solved which is more than a complicated problem.In engineering,the role of NSF may lead to the uneven settlement of the upper structure based.Many buildings may appeared excessive settlement,tilt or cracking phenomenon of the building because of the effect of NSF.In this paper,it is discussed with NSF,so people may make high attention to NSF.

The Relationship Between p_s Value of Static Cone Penetration and Physical and Mechanical Properties of Soil

Ding Xiaoqing, Lin Biming

2014, 28(4): 201-204. doi: 10.3969/j.issn.1007-2993.2014.04.009

[Abstract](30) [PDF 2123KB](7)

Abstract:
The author combined with a specific instance of the project to explore the correlation analysis of p_s value and indoor test indicators of the soil,and obtained some empirical formula.Applying these formulas,we can use p_s value deriving the engineering properties of soil,but also soil can be divided according to the curve type of p_s value and p_s-H.

Sensitivity Analysis of Influencing Factors of Fill Slope

Duan Yongkun

2014, 28(4): 205-211. doi: 10.3969/j.issn.1007-2993.2014.04.010

[Abstract](26) [PDF 1902KB](8)

Abstract:
This paper takes a fill slope in Chongqing for example,uniform design method is adopted to arrange experiment,regression analysis is used to compare and analyze the differences that each factor influences on the stability of slope.The sensitivity of every influencing factor is obtained.The main factors affecting the slope stability are internal friction angle of filler φ,slope gradient α and the groundwater level H_w.Based on the sensitivity of influencing factors,more pertinence engineering measures will be taken to the design and construction of fill slope.

Simple Discussion on Aerodrome Building Location Survey

Cai Huaien

2014, 28(4): 212-213. doi: 10.3969/j.issn.1007-2993.2014.04.011

[Abstract](36) [PDF 501KB](5)

Abstract:
Aerodrome building location survey can give scientific view for decision makers and project operators who are engaged in aerodrome building construction.Based on engineering experiences,this paper discusses the aim,contents,process and methods of the aerodrome building location survey.

The Treatment Countermeasure about Karst Funnel and Sinkholes

Liu Dongyan

2014, 28(4): 214-217. doi: 10.3969/j.issn.1007-2993.2014.04.012

[Abstract](31) [PDF 6408KB](11)

Abstract:
The article introduces the characteristics of karst funnel and sinkholes.Combined with the engineering example,the article recommends reconnaissance means of geological mapping and geological radar combined.The main factors affecting the stability of roadbed in karst are analyzed.The karst funnei and sinkhole mainly take the leap,reinforcement,blocking treatment measures.

2014 Vol. 28, No. 4