The 2018 Membership Conference of the Shield Tunnel Remanufacturing Innovation Strategic Alliance was held in Guangzhou.

On November 16, the "2018 Membership Conference of the Shield Tunneling Remanufacturing Innovation Strategic Alliance" was grandly held in Guangzhou.

2018-11-23

Luoyang Jiujiu Technology Co., Ltd. 20th Anniversary Celebration & Yuntai Mountain Resort Retreat

In August 2016, to celebrate the company’s 20th anniversary, a Yuntai Mountain resort getaway was held under the theme "Moving Forward Together, Creating Brilliant Futures." Yuntai Mountain, historically known as "Fufu Mountain," earned its second name due to its towering peaks and the perpetual clouds and mist that shroud the mountain throughout the year. The terrain is rugged and steep, with pristine forests blanketing the entire area. Towering over the landscape are deep, serene valleys dotted with crystal-clear streams and tranquil pools, complemented by countless breathtaking waterfalls and cascading springs. The scenery is nothing short of picturesque, featuring uniquely shaped rock formations that seem straight out of a dream.

2016-11-21

China Railway Equipment once again stuns the world.

On December 25, the world's largest rectangular pipe jacking machine with a large cross-section, "Kaotuo," independently developed and manufactured by China Railway Engineering Equipment Group Co., Ltd., rolled off the production line at Dalian Qianyi Manufacturing Base. Luoyang Jiujiu Technology Co., Ltd. also contributed to the project by participating in its technical research and development efforts.

2016-01-06

Qiongzhou Strait Cross-Sea Bridge

The "Qiongzhou Strait Cross-Sea Engineering Planning Study Report," jointly prepared by the Ministry of Transport, the Ministry of Railways, and the provinces of Guangdong and Hainan, has now been completed. The report identifies the construction of a combined road and rail bridge connecting Denglujiao in Xuwens County, Guangdong Province, to Daolunjiao in Chengmai County, Hainan Province, as the preferred solution for the Qiongzhou Strait cross-sea project. The bridge’s offshore section will span 26.3 kilometers—making it the second-longest bridge in the world, behind only the newly completed Hangzhou Bay Bridge.

2015-12-28

Luoyang Jiujiu Technology Co., Ltd. Successfully Held the 2015 Baoduzhai Red Tourism Event

In August 2015, our company organized a two-day trip to Luanchuan Baoduzhai, themed "Remembering the Martyrs and Revisiting Our Red History." Baoduzhai boasts rugged, undulating terrain that stretches endlessly, with its steep and perilous landscape. Back then, PLA soldiers bravely carried explosive packs and scaling ladders, defying enemy fire to liberate this ancient fortress—once home to generations of impoverished villagers trapped in dire suffering. At the site, employees paid tribute at the Heroes' Monument, watched a documentary chronicling the liberation of Baoduzhai, and witnessed firsthand the inspiring scenes of heroic martyrs fearlessly battling through relentless challenges to safeguard their homeland and protect their cherished community.

2015-09-17

Our company's ultra-large-diameter engineering drill bits have been perfectly applied in key national projects.

On June 3, 2015, the Z05 main tower pier of the main bridge over the Guyu Gate waterway for the Fuping Railway’s Pingtan Strait Dual-Use Bridge—a key national project—successfully completed the concrete pouring of a 4.5-meter-diameter bored pile. This pile currently represents one of the largest-diameter foundation piles in the history of bridge construction. The drilling bit used for this borehole was custom-designed and manufactured by Luoyang Jiujiu Technology Co., Ltd., featuring an innovative structural design and robust welding techniques, which provided a solid foundation and ensured high-quality results for the smooth completion of Bored Pile No. 4 at the Z05 pier of the Pingtan Strait Dual-Use Cross-Sea Bridge. Additionally, all eight 4.5-meter-diameter drill bits and 20 4.0-meter-diameter drill bits supplied by our company were seamlessly integrated with the corresponding drilling rigs for this critical project.

2015-06-11

Warmest congratulations on the successful completion of our company's shareholding reform!

Our company, through a resolution passed at the shareholders' meeting on March 10, 2015, officially changed its name from "Luoyang Jiujiu Technology Development Co., Ltd." to "Luoyang Jiujiu Technology Joint-Stock Co., Ltd." The subsequent business registration update was completed on March 31, 2015, marking the official transformation of our company type from a "Limited Liability Company" to a "Joint-Stock Company."

2015-04-06

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