岩土工程技术

Application of Hierarchy Analysis in Scheme Optimization of Deep Excavation Protection

1999, 13(1): 3-8.

[Abstract](25) [PDF 337KB](3)

Abstract:
In the course of construction project bidcall, negotiation is a hard nut to crack. The optimal bracing of deep foundation pit is elected by The Analytic Hierarchy Process in the paper. This method is scientific and the result is equitable.

Some Improvement of Design and Calculation of Cantilever Retaining Pile for Deep Excavation

1999, 13(1): 9-12.

[Abstract](29) [PDF 176KB](5)

Abstract:
The statical equilibrium method is the simpler and clearer one for design of cantilever retaining pile, and safe and reliable. Firstly,the selection of soil shearing strength indexes, such as the cohesion c and the internal friction angle φ, is discussed. Secondly, the improvement on the laternal earth pressure and the analysis of water pressure acting on pile are introduced. Thirdly, the structural calculation of cantilever retaining pile is expounded systematically, and some more practical formulae are formed. Finally an example is given reader to refer.

Calculation of Horizontal Stiffness Coefficient of Bracing Structure in Foundation Excavation

1999, 13(1): 13-16.

[Abstract](40) [PDF 167KB](7)

Abstract:
The methods to calculate the horizontal stiffness coefficients of beam at the top of pile and bracing system and soil anchor are discussed in foundation excavation.

Protecting Technique of Composite Soil-nailing Wall with Retaining Water

1999, 13(1): 17-21.

[Abstract](43) [PDF 371KB](7)

Abstract:
The applied ranges and general characteristics and structural shapes and deformation-controlled technique etc. are researched on the composite soil-nailing wall with retaining water according to its engineering practice in Shenzhen area, and the calculating method of its design is put forward.

Supperimposed Earth Pressure of Retaining Wall with Continuous Local Load

1999, 13(1): 22-26,40.

[Abstract](48) [PDF 245KB](15)

Abstract:
The Boussinesq and Flamant solutions for superimposed stress, combined with the Rankine earth stress theory, can be applied to calculate the active and passive superimposed stresses of retaining wall with vertical rectangular and strip load. The method can more accurately deal with the type and location and area of load and the influence of limit equilibrium state than the other methods can do, and can reveal the propagating change of external load by the fill, the calculating result is smaller. The calculations of some examples show that if the load location is of a distance away from the wall, the stress is zero at top of wall, but it will increase along the depth, and upto a value then decrease. If the load is located at the top of wall, the maximum stress is at the top and it will decrease along the depth. The stress in the case is greater than that at the first situation. Under the same condition, stress caused by strip load is greater than that caused by rectangular load.

Spatial Effect of Protecting Structure of Deep Excavation Analyzed by 3DFEM

1999, 13(1): 27-29,33.

[Abstract](24) [PDF 164KB](5)

Abstract:
The spatial effect is researched on the protecting structure of retaining pile by the three-dimensional finite element method(3DFEM), and compared with the other methods the better result is obtained.

Some Discussion on Settlement of Pile Calculated by Mindlin Method

1999, 13(1): 30-33.

[Abstract](93) [PDF 164KB](11)

Abstract:
The settlement calculated by the Mindlin method is more approaching to one of reality for pile foundation with the increase of tall-storey and supertall-storey buildings in Shanghai and the appearance of composite pile foundation to control settlement. The some problems calculated the settlement of pile foundation by the Mindlin method are discussed. Compared with the other methods its calculating result is better.

Determination of Neutral Point to Consider Negative Skin Resistance in Pile Foundation Design

1999, 13(1): 34-36.

[Abstract](92) [PDF 133KB](11)

Abstract:
According to the definition of negative skin resistance the position of neutral point is determined based on a project, its result is in accord with one given in the code. The influence of negative skin friction is also analyzed.

Experimental Analysis of Vertical Bearing Capacity for Cast-in-place to Tamp Broken Stone in Hole Bottom

1999, 13(1): 37-40.

[Abstract](36) [PDF 297KB](5)

Abstract:
By the analysis of bearing capacity of tamping pile and common pile, it is believed that the resistance force will increase by times because of the improvement of soil properties at pile end after tamping broken stones. The range of ultimate end resistance for tamping pile is put forward, it provides the basis for pile foundation design.

Laboratory Experimental Study on Soft Foundation Reinforced by Flyash Pile

1999, 13(1): 41-46.

[Abstract](27) [PDF 439KB](3)

Abstract:
By the indoor model test of flyash pile, the deformation and failure characteristics of flyash pile, the change pattern of pile and soil stress and the mechanism of flayash pile to reinforce soft foundation are analysed. Firstly, the soil stress increases gradually with the load increasing, and the pile body stress increases rapidly, the pile will yield and the composite foundation will begin to failure when the pile stress reaches the peak strength, then the stress will decrease after the peak strength; Secondly, the stress ratio of pile to soil changes with the load and time, and it is related to the pile soil modulus ratio and the length diameter ratio of pile. So the pile soil stress ratio should be considered a variable when the pile foundation is designed; Finally, because of the bigger strength and good permeability of flyash pile, its compacting and underpinning functions and time effect are all prominent when soft foundation reinforced. Therefore flyash pile is proved to be a kind of more suitable flexible material pile.

The Computation of Pore Pressure in Saturated Sand

1999, 13(1): 47-49.

[Abstract](65) [PDF 212KB](7)

Abstract:
The pore water pressure is divided into three parts, i.e, volume-strain pore pressure, pulsation-pore-pressure and seepage pore pressure. The first one is discussed carefully in the paper.

On Physical Base of Transformation from Cohesive Soil into Incohesive Soil

1999, 13(1): 50-52,57.

[Abstract](53) [PDF 169KB](6)

Abstract:
The physical base of transformation from cohesive soil into incohesive soil is discussed in terms of the Mohr Coulomb failure criteria, and the some examples are given. The limitation which regularity knowledge obtained by the indoor model test for incohesive soil is applied to instruct the corresponding cohesive soil project is pointed out.

Application Research of Dynamic Compaction Composite Cement-soil Pile Foundation

1999, 13(1): 53-57.

[Abstract](39) [PDF 378KB](4)

Abstract:
According to the characteristics of cement soil and dynamic compaction construction, combined with the some project examples, the effect of dynamic compaction cement soil column on foundation design and construction is researched. It is expounded that is feasible in safety and reasonable in economy for foundation treatment, and a few problems to be considered in design and construction are expounded, too. It has been experimented in tall storey buildings, and good results have been obtained.

Discussion on Name of Silt

1999, 13(1): 58-60.

[Abstract](31) [PDF 244KB](5)

Abstract:
Silt is neither clay, nor sandy soil. It has the distinctive character. The existing problems for silt name are discussed. Its named method and suggestion are put forward.

1999, 13(1): 61-64.

[Abstract](18) [PDF 348KB](3)

Abstract:

1999 Vol. 13, No. 1