Application of BIM in Neelum-Jhelum Hydropower Project in Pakistan

Guo Xiao，Han Zhuo，Geng Qingzhu，Xu Ting
（China Water Resources Beifang Investigation，Design and Research Co.Ltd.，Tianjin，300222）

In view of several typical cases of problems caused by complex shape or structure in the construction of Neelum-Jhelum Hydropower Project in Pakistan，BIM technology is used to solve these problems.This paper focuses on three-dimensional visualization of BIM，and points out that BIM technology can make design，construction，supervision consulting companies and other participants more intuitive to communicate the problems encountered，thus it can solve the problems more conveniently and quickly on the same platform，and greatly shorten the construction period and save cost.

Key words:BIM，hydropower project construction，reinforcement manufacture and installation，formwork manufacture and installation.

Calculation on New Type Lining Structure of A Deep Buried and High Ground Temperature Diversion Tunnel in China

Sun Qichen，Wang Licheng，Zhao Yakun，Zhao Xiaolu
（China Water Resources Beifang Investigation，Design and Research Co.Ltd.，Tianjin，300222）

In combination with the reinforcement problem of lining structure of a deep buried and high ground temperature diversion tunnel in China，finite element analysis software is used to study the stress characteristics of rock and supporting structure under the coupling of temperature and stress through thermal-structural coupling method.The results show that the influence of low temperature water diversion on the temperature field of rock and supporting structure is significant，and the reinforcement area will be greatly increased.In order to ensure the safety and economy of diversion tunnel，a new type of lining structure has been adopted，which has significant effect on reducing the temperature stress of lining and improving the stress of lining structure.

Key words:high ground temperature，tunnel，lining structure.

Construction Model and Technical Analysis of Sponge City

Zhang Zongliang
（China Water Resources Beifang Investigation，Design and Research Co.Ltd.，Tianjin，300222）

In recent years，the concept of sponge city has received tremendous repercussions throughout the country.Since the Ministry of Construction launched the pilot project of sponge city construction in 2015，it has achieved good results by adopting the“point-toface”approach.River system is the skeleton of a city sponge pattern and plays an important role in the construction of a large sponge system.This paper first summarizes the development methods adopted in the development and construction of sponge cities in China，then further discusses the construction mode of sponge system，and finally introduces the common construction technology in the process of sponge city development.

Key words:sponge city，development mode，construction mode.

Application of Dry Hole Acoustic Wave Method on Measuring the Loosing Circle of Surrounding Rock of Tunnel

Sun Zhixin，Zhao Qiu，Zhao Hongpeng
（China Water Resources Beifang Investigation，Design and Research Co.Ltd.，Tianjin，300222）

Due to the rock mass is affected by blasting，mechanical excavation，rock loosening and unloading，and many other factors，the stress in surrounding rock of tunnel will be redistributed，and a stress release zone on the surface of surrounding rock will be formed，which is easy to be loosened and destroyed if it is not treated or strengthened in time.Therefore，it is of great significance for excavation，grouting reinforcement and stability evaluation of tunnel to correctly recognize and test the loosening change characteristics of surrounding rock.This paper introduces the basic principle，technology and results analysis of acoustic wave method for testing the loosening circle of surrounding rock.The curve of acoustic P-wave velocity with depth of hole is obtained by using dryhole acoustic wave method.The thickness range of loosening circle of rock is determined by the loosening circle，stress concentration zone and elastic wave velocity characteristics of original rock，which provides scientific basis for stability evaluation and support design of tunnel.

Key words:tunnel，dry-hole acoustic wave method，surrounding rock，loosening circle.