Our company has successfully passed the High-Tech Enterprise certification three times in a row.

Luoyang Jiujiu Technology Development Co., Ltd. applied for and successfully obtained High-Tech Enterprise certification in 2008, underwent a re-evaluation as a High-Tech Enterprise in October 2011, and was re-certified as a High-Tech Enterprise again in October 2014.

2015-02-06

Classification of Shield Tunneling Methods

There are many types of tunnel boring machines, and they can be classified in various ways. Based on the excavation method—whether manual or mechanical—they are divided into hand-excavated shields and mechanized shields. Additionally, depending on how the working face supports the soil, shields can be categorized as open-type or closed-type. Finally, shields can also be classified according to their design and excavation techniques, falling into either hand-excavated or mechanically operated categories.

2013-08-28

Wear Characteristics of Wear-Resistant Hammer Heads Used in Cement Plant Limestone Crushing

The silicon content in the chemical composition of limestone directly affects the service life of hammer heads—higher silicon levels lead to shorter lifespans. Ideally, the silicon content in limestone should remain below 2%. On the other hand, the compressive strength of limestone is closely linked to hammer head durability: the higher the compressive strength, the less brittle the material becomes, but paradoxically, this also reduces the hammer head's lifespan. Hammer head selection and manufacturing quality play a critical role in determining how long a hammer head will last. Historically, the materials used for crusher hammers in the cement industry were primarily high-manganese steels, with ZGMn13Cr2 being the preferred choice due to its excellent wear resistance. However, even this material struggles under conditions involving high-silicon content and extremely hard limestone—and when combined with unfavorable operating conditions, its lifespan can drop dramatically. For instance, a single set of hammers might fail after processing just 100,000 tons of material. With advancements in hammer technology, newer materials have emerged, such as ultra-high-manganese steel and dual-alloy composite wear-resistant hammers. Ultra-high-manganese steel, specifically ZGMn18Cr2MoRe, features an increased manganese content compared to the traditional ZGMn13Cr2. This enhancement aims to boost the material’s hardness during heat treatment, thereby improving wear resistance and extending the hammer’s service life. Yet, there’s a practical limit to how much manganese and alloy elements can be added, as increasing these components often compromises the material’s toughness. As a result, ultra-high-manganese hammers are not recommended for applications involving significant impact forces. Dual-alloy composite wear-resistant hammers come in three main designs: First, a layer of hard alloy is welded onto the working surface of the hammer, significantly enhancing its abrasion resistance. Second, during casting, the alloy content (particularly chromium) in the hammer’s working area is carefully controlled to maximize wear performance. Finally, hard alloy rods or blocks may be embedded directly into the hammer’s working zone for added durability. Ultimately, the quality of hammer head manufacturing depends heavily on factors like precise geometric dimensions, carefully calibrated alloy compositions and contents, as well as the depth and uniformity of the heat treatment process. Additionally, operational conditions during crushing activities have a profound impact on hammer life: for example, the particle size of the limestone greatly influences hammer durability; moisture content in the limestone directly affects wear rates; frequent blockages in the crusher’s discharge grate, coupled with continued operation despite these obstructions, can severely shorten hammer life; and finally, the presence of impurities in the raw limestone material can also significantly degrade hammer performance. Each of these factors plays a crucial role in determining the overall longevity of wear-resistant hammers.

2013-08-27

Analyzing 4 Factors That Influence Hammer Head Lifespan

Crusher hammer heads include: hammer crusher hammers, compound crusher hammers, sand-making machine hammers, fine-crushing machine hammers, and stone-crushing machine hammers, among others. Their lifespan depends on the following four key factors: 1. The physical properties of the mineral and the characteristics of its accompanying materials (such as abrasiveness to metal, soil content, moisture levels,黏塑性 [viscoplasticity], compressive strength, etc.). 2. The rationality of the machine’s internal structural design. 3. The appropriateness of the material selection for the hammer head and the quality of its manufacturing process. 4. The proper operational techniques employed during use. The first factor is an inherent, objective condition—something that exists naturally and must be understood accurately from the outset. As for the second factor, it involves making necessary adjustments within the machine to ensure optimal performance tailored to both the properties of the material being processed and the specific requirements of the production process.

2013-08-27

Non-Destructive Construction Techniques for Large-Diameter Pipelines

In recent years, Tianjin has seen rapid advancements in its urban infrastructure development, with the city steadily expanding in size. As a result, sewage discharge volumes have been on the rise. At the same time, efforts to protect rainwater resources, implement stormwater-sewage separation systems, and enhance the city's flood-control capabilities have driven significant year-on-year growth in the scale of Tianjin’s newly constructed underground drainage networks. Meanwhile, with the city’s traffic volume steadily increasing—leading to longer and wider roads—the length and diameter of rainwater and sewage pipes beneath road surfaces have also grown substantially, ensuring that the city’s infrastructure can effectively meet its evolving needs.

2013-08-27

China's domestically developed tunnel-boring equipment has achieved a localization rate of 60 percent.

The prototype slurry balance tunneling machine "Jin Yue," developed and built by five organizations including Shanghai Urban Construction Tunneling Co., Ltd., boasts full independent intellectual property rights and a diameter of 11.22 meters. It was successfully deployed in the Dapu Road twin-tunnel project—a key infrastructure supporting the Shanghai World Expo—and completed the 1,472-meter-long tunneling task flawlessly. During construction, the "Jin Yue" slurry balance shield machine operated smoothly, showcasing the exceptional maneuverability and precision of domestically produced shield equipment, especially when it came to protecting nearby structures and navigating ultra-small-radius tunneling sections.

2013-08-26

Conference Paper Directory

**Table of Contents for the 9th National Symposium on Large-Diameter Engineering Well Construction Techniques** 1. **Ultra-Large Diameter Bridge Composite Pile Foundation System** Jiang Wei, Diao Xinhong (School of Civil Engineering, East China Jiaotong University, Nanchang, Jiangxi) 2. **Trenchless Construction Techniques for Large-Diameter Pipelines** Ding Yiming (Branch No. 5, Sixth Company, Tianjin Urban Construction Group, Tianjin, 300250) 3. **Application of Roller Cutter Bits in Large-Diameter Mine Shaft Construction: Key Considerations** Chao Huanqing, Wang Hanzhang Luoyang Jiujiu Technology Development Co., Ltd. 4. **Drilling Construction of Large-Diameter Foundation Piles in Fractured and Sliding Layer Geology** Zhang Jinlin, Xie Tang (Luqiao Huannan Jinlin Foundation Engineering Co., Ltd., Zhongshan, Guangdong) 5. **Construction Techniques for Large-Diameter Deep Bored Pile Foundations under Special Conditions: A Case Study from the Tianjin Binhai New Area Light Rail Project** Zhu Mingsheng, Xie Kongjin, Gai Jianguo, Xu Hongwei, Li Liangliang (Shandong Zhengyuan Construction Engineering Co., Ltd., Jinan, 250014) 6. **Leveraging Technological Advancements to Drive Enterprise Growth** Chen Hongru, Li Shijing (Shenzhen Ruzi Niu Construction Engineering Co., Ltd.) 7. **Drilling Techniques for the Yichang Yangtze River Bridge on the Yiwan Railway** China Railway Major Bridge Engineering Group Co., Ltd. 8. **Pile Foundation Construction and Project Management for the Madura Bridge in Indonesia** Wang Jianjun, Liu Mufeng, Yi Jianying, Mao Shanyuan (Hunan Foundation Engineering Co., Ltd., No. 76, Section 3, Wanjiali Middle Road, Changsha, 410014) 9. **Preliminary Study on the Relationship Between Scraper Entry Angle, Drilling Pressure Ratio, and Hole-Forming Efficiency in Comb-tooth Drill Bit Applications** Gu Yuanxing Shanghai Guanglian Construction & Development Co., Ltd. 10. **Application of Horizontal Directional Drilling Technology in Tunnel Engineering** Li Shuhai, Zhou Haishong (Shanghai Guanglian Construction & Development Co., Ltd.) 11. **Practical Experience in Handling Downhole Incidents During Large-Diameter Bored Pile Construction** Li Shuhai, Zhou Haishong, Wang Yuanman (Shanghai Guanglian Construction & Development Co., Ltd., Shanghai, 200436) 12. **A New Approach to Pipeline Replacement Using Horizontal Directional Drilling Technology** Li Shuhai (Shanghai Guanglian Construction & Development Co., Ltd., Shanghai, 200438) 13. **Application of Long-Tube Canopy Advanced Support Systems in Tunnel Portal Construction** Ou Lingyong Hunan Road & Bridge Construction Group 14. **Monitoring and Measurement during Snowfeng Mountain Tunnel Construction: Analysis of Surrounding Rock Stability** Cao Caiyong (Hunan Provincial Road & Bridge Group Co., Ltd., Changsha, Hunan, 410000) 15. **Analysis of Karst Geological Conditions and Pile Foundation Construction Methods** Xie Yongchun, Yan Jiong Hunan Road & Bridge Construction Group 16. **Development of the Self-Propelled Reverse Circulation Drilling Rig Model GFC-120** Zhang Xikun, Song Qiufeng Hebei Institute of Construction Exploration & Research, No. 58 Jianhua South Street, Shijiazhuang 17. **Discussion on Temperature Control Techniques for Large-Volume Concrete** Li Ziquan Hebei Institute of Construction Exploration & Research, No. 58 Jianhua South Street, Shijiazhuang, 050031 18. **Prevention and Remediation of Accidents in Impact Bored Pile Construction in Karst Regions** Zhao Jianqiu Hebei Institute of Construction Exploration & Research, No. 58 Jianhua South Street, Shijiazhuang 19. **Summary of Construction Experience for Rock-Embedded Bored Piles in Areas with Developed Karst Features** Li Chenyan, Zhang Peng Hebei Institute of Construction Exploration & Research, No. 58 Jianhua South Street, Shijiazhuang, 050031 20. **Calculation Method for Settlement Curves (σ—y) of Sutong Bridge Bored Piles** Shangguan Xingjiang, Jiang Wei (East China Jiaotong University) 21. **Load-Bearing Capacity Analysis of Sutong Bridge Test Piles** Sutong Bridge Construction Command 22. **Sutong Bridge Bored Pile Construction Platforms** China Communications Second Navigation Engineering Bureau, China Communications Second Highway Engineering Bureau 23. **Construction of Ultra-Long Bored Piles for the Sutong Bridge** China Communications Second Navigation Engineering Bureau, China Communications Second Highway Engineering Bureau

2013-08-26

The Ministry of Railways will receive over 200 billion yuan in financing support, while China South and China North Locomotives have secured tens of billions in outstanding payments.

The Ministry of Railways will soon receive over 200 billion yuan in financing support, which will help with debt repayment, advance key projects, and optimize and refine accompanying initiatives. Thanks to government backing, the railway sector—previously grappling with severe funding challenges—will see a significant easing of its financial strain.

2013-08-26

The seventh tunnel boring machine for Xi'an Metro Line 1 departs from Changlepo.

The No. 12 construction project of Metro Line 1, undertaken by China Railway Eleventh Bureau Group, includes three shield tunnel sections: Changlepao–Wanshou Road Station, Wanshou Road–Tonghuamen Station, and Tonghuamen Station–Kangfu Road Station. This project also features two mined tunnels and one ventilation shaft within the tunnels, with a total length of 3,748.85 double-track meters. Construction officially began on March 18, 2009, and the project is scheduled for completion in early 2012.

2013-08-26

In 2010, four expressways connecting China's Yunnan province to Southeast and South Asia were completed.

Relevant authorities in Yunnan Province have learned that construction is accelerating on four high-grade highways in the province, which are oriented toward Southeast and South Asia. By 2010, the Yunnan sections of these four major international corridors—connecting to both regions—will be fully completed.

2013-08-26