Abstract:The forming, stable condition, distribution and oversea research tendency of gas hydrates are briefly introduced in this paper, and the function and technology problems of exploration drilling of gas hydrates are elaborated, and the working thinking of exploration boring of gas hydrates in China is presented.

Abstract:In view of development of national economy and environmental protection, necessity of researching wet shotcrete technology is discussed in this paper based on rebound reduction, dust reduction and construction quality of wet shotcrete. Jet regular pattern of wet shotcrete is analyzed based on hydrodynamic theory. And calculating method of optimum shot velocity is got.

Abstract:Empirical formula of downward load of pile foundation is presented based on analyzing characteristic of negative frictional resistance of pile foundation. Feasibility of the proposed formula is verified by a deviation correction engineering of deep pile foundation, which supplies theoretical foundation for application of negative frictional resistance of pile foundation on building inclination correcting engineering and supplies an effective method for building inclination correcting technology of deep pile foundation.

Abstract:According to the load of tripping, driving system of drill should have rigid output performance and regulating performance approximate to constant power. Mechanized tripping method with AC inverter driving system and it's examples is discussed.

Abstract:Structure, overall design and working condition of the 100 kN hydraulic winder is introduced in this paper. The design of power transmission system of hydraulic winder is theoretically analyzed, which supplies design data for developing the same kind of product.

Abstract:介绍了爆破地震动强度的主要因素及经验公式 ,分析了利用最小二乘法求场地系数K、α值方法的不足之处 ,提出最大似然法求解K、α值的新思路 ,并用实例证明了其具有更高的预测准确度