Dayaoshan double track tunnel with a length of 14.3 km and a highest overburden of 900m is a key item of the project doubting Jing-Guang Railway (Beijing to Guangzhou), Beijing under construction. The field results of tests and measurements performed near Huashipai inclined shafts 1 and 2 are described. Measurements of initial stress, monitoring of secondary stress, monitoring of convergence and displacements of the tunnel’s side wall and deflectometer are discussed. A general assessment of the stability of tunnel is presented according to measured data and numerical analysis.

In this paper, a great quantity of computation on the pile bearing capacity are made by using the wave equation computer program with successively varying input parameters. The effect of each parameter on the pile bearing is analysed. It is shown that all the parameters can be classified into two groups: the intrinsic parameters held by the pile-soil system and the auxiliary parameters held by the pile-hammer system. The intrinsic parameters, including the quake of soil, the visco damping coefficient, the elastic moduli of pile material, the cross section area and the length of the pile, play the dominant role in the determination of the pile bearing capacity. The auxiliary parameters, including the hammer weight, the hammer fall, the spring constant of the cap-block, the coefficient of restitution of cap-block and pile-cushion, and the efficiency of the hammer, etc., only influence the curves Ru = ｆ(S) or Ru =ｆ(N) but not change the value of the actual bearing capacity of the pile. From the analysis it is also indicated in the paper that the quake value of the soil, besides the intrinsic parameters held by the pile itself, is the mast influential factor on the pile bearing capacity.

This paper firstly describes the development history and the present situation of soil mechanics, them shows features and the complicacy of geotechnical engineering and soil mechanics. All this may lead to the conclusion that the problems concerning soil mechanics and geotechnical engineering cannot be perfectly solved only with the present soil mechanics theory and numerical method. The centrifugal modelling test, owing to its replication property of in-situ stress level of structures, can be used to predict the working condition of geotechnical engineering, or to verify some principles of soil mechanics. For this reason, this testing method is getting popular. However the centrifugal modelling test just play a complementary role rather than a repellent role to the present research methods.

This paper, comparing the dynamic test results of mudstone (silty clay) with the static ones, verifies influence of cyclic loading and loading rates on the strength of mudstone. It is found that the dynamic strength is higher than the static strength. In the case of rapid loading (rising time of pressure is 10ms ), the unconfined compressive strength for this type of soil in dynamic test is 2.3 to 2.9 times as high as that in static tests, and the strength index, Cd , is about 2.8 times as great as Cs , but ∅ values are approximately equal to each other. Repeat loading (up to 3600 cycles) has no great influence on the strength of mudstone, and under the condition of unconfined loading, the fatigue strength of mudstone is somewhat lower than its statically strength.

The axisymmetric finite element technique is used in this paper to analyze the creep effects on pole foundation. Generalized Kelvin model and Bingham model are proposed to simulate the viscoelastic and viscoelastic behavior of soil respectively. Viscoelastic and viscoelastic strain incremental formulas are derived for interface elements and soil elements around piles and the axisymmetric elastic-viscoelastc-viscoplastic finite element program is compiled. Creep effects on the settlement of poles, the building load carried by raft and the distribution of stresses along piles are analyzed. In addition, the behavior of interface between pile and soil are investigated through experiment.

This paper from the point of regional, based on the statistics and analyses on a great number of geotechnical test, deals with the geneses and composition of Hainan soils and the distribution law of various soils in the Hainan Island, the physico-mechanical properties of the soils are also discussed in the paper. All this is the summary on the work during the past three decades. The research results listed in the paper can be used to a certain extent as a reference for the development of the Hainan Island.

A great quantity of computer-sided data has been made by means of the normalized curve method of estimating consolidation settlement for saturated cohesive subsoils in this paper to research into regularities of subsoil settlement varying with the shapes of loading area and with the foundation depths while the total loads and the loading area are constant. A proposal of using the regularities to adjust the settlement of foundations of multi storied residence buildings is given which will make the design more reasonable. Finally, the estimating method is cheeked experimentally by the observed results of an in-situ loading test.

This paper deals, in detail, with the large testing equipment for researching on mechanical properties of deep bearing beds—high pressure triaxial apparatus for soils. Through triaxial undrained consolidation test, the paper describes the whole auto procedure of the system (including real time acquisition of data, auto-control, result output and auto drawing) and the soft and bard wares of the testing apparatus.