Gas Spring Shield extrusion rubber cord to make it through the portal valgus , and push the gas spring compressive deformation, gas spring reaction force acting on the hinge plate by a rubber cord , rubber cord can be pressed tightly shield shell, thereby forming a stable sealing environment. Steel collar by welding and with the bolt hole circle are connected by forming a piece having a greater stiffness to ensure safe operation of the entire apparatus. Shield to complete the final part of the tube sheet assembly continue to push forward until the shield out gas springs anti socks devices. In this paper, based on the traditional installation hinge plate device can provide constant pressure on the kinds of gas springs, formed a kind of anti- anti-risk socks gas spring device ( hereinafter referred to as the anti- socks spring device ) , and successfully applied to a range of Zhengzhou Metro shield of the project , to reach the project risk shield provided new control technologies and ideas. Zhengzhou City, a project of Urban Rail Transit Line 1 0 Contract segment , where Seven Mile Creek Station - a new Zhengzhou station tunnel is an integral part of the bid , the use of two 6140mm diameter earth pressure balance shield machine articulated ) construction . 5400mm internal diameter tunnel ring segment width 1.5m, thickness of 0.30m. Shield tunnel section at the hole located in the silt, silty clay , fine sand layer, just above the water table depth shield hole section , the tunnel overburden approximately 321m. Shield hole using a combination of deep mixing pile rotating pile reinforcement. Shield Anti hole socks device works as shown , the device is mainly composed of gas springs , hinges, plates, steel pads , rubber cord and other components. Anti socks gas spring seals Shield arrived at the scene before the installation is complete . At this point, the rubber cord tightly pressed segments . Grouting grouting hole through the pipe piece out , quickly filling the gap between the portal and the tube sheet , thereby blocking portal . After the slurry solidified mud blocking the moving circle , remove the shield hole socks anti- sealing device , shield hole end of construction . Shield arrival process , the entire sealing device can withstand tremendous pressure on land and water , circle the drain hole to prevent mud , water leakage , to ensure the safety shield , smooth hole. The key is that the whole device using the gas springs , gas springs generally cylinder , the piston ( rod ) , the seal member and the external connection component . High-pressure nitrogen or inert gas and oil in the cylinder forming the circuit . So that the damping piston rod chamber and rodless lumen, the chamber pressure so that the two are equal . Use two-chamber compressibility produce elastic force area difference and gas. Gas spring with a compact structure , large working stroke ; smooth motion , can play a buffer role in damping ; in the expansion process can provide constant pressure on the hinge plate , and installation is simple, safe and reliable. Anti socks gas spring device is designed primarily considered anti socks gas spring device is designed to the following questions : device is designed sealing pressure : Requires device can withstand shield hole reinforcement failure , formation water pressure. Device diameter : Requires device when the axis of the shield with the greatest deviation hole passed devices. Gas Spring Selection : Based on the above two points to determine the gas spring pressure and stroke work . Rubber cord : rubber cord width must be adapted to the length of the gas spring , depending on the location and the opening hole of the bolt hole circle . Set several trapezoidal ribs to increase the overall stiffness of the steel ring device . Device block : block device to consider transportation, installation , dismantling work . Steel ring dimensions must consider the interference of the internal structure Foundation . By requiring the above design requirements, the construction and analysis of the process , after the design of the shield reaches demonstrated anti socks gas spring means shown in Figure 3 . As the gas spring device is connected by bolts anti socks with holes in the production circle and circle hole and the installation process will produce some errors , so as to ensure a smooth installation device , you need to be reviewed the following measurements: the upper and lower halves of embedded hole circle prefabricated steel bolt hole door distance along the width of the ring plate prefabricated steel ring ; ring into the transverse hole , the diameter of the longitudinal and design errors ; number and spacing of holes ;
The depth and length of the screw thread . Shield measure through the shield in front of which the position is reviewed to confirm shield gesture, posture assessment and formulation shield shield hole when the hole axis segment of construction , propulsion control values and construction programs , such as the slope of the important basis , so that the shield is always predetermined program implementation in this phase of construction , with a good attitude hole in the shield in place on the base to receive accurate . Besides the need for promoting the right lane tunnel shield hole assembly ring number and mileage are reviewed to determine the final part of the tube sheet accurate mileage .
Gas Spring Shield receiving dock and placed depending on the exact track of the orientation Portal for accurate placement of the shield base stakeout . Baseline measurements in accordance with loft , hanging into the underground place assembly, welding base installation. Base by flat slope put the base in place, be supported reinforcement to strengthen its overall stability. Base and cave walls lined circle hole spacing should ensure the new anti-risk device installation space. In order to make a good guide when the shield hole , put the guide rails on the hole circle. At the bottom of the hole guide rails placed two rings , rubber cord extends to seal the hole at ( flush with the walls lined hole circle ) . Two guide rails on the base of the shield extends to the lower part of the new risk-resisting steel ring structure of the device . Device installation process to install the device shown in Figure 4 . First erection mounting portions 12d slope after seeding grass sprouted yet , this is the grass immature actions, soaking germination methods available treatment, the grass soaked in warm water with 30 ℃ 12h, 7d after seeding general can germinate. Some uneven slope of grass growth , which is mainly caused by the uneven distribution of seeds , attention to strengthening the spray liquid is stirred at seeding should make seeds evenly distributed.
Drought occurred during the latter part of the conservation and management , pest phenomenon , according to the "small number " principle watering and spraying of pesticides in order to ensure the normal growth of seeds . Recipe soil layer with soil too sticky , or in order to improve the ability of anti-erosion and slope to join the solidification of cement , are detrimental to the growth of the seeds , then can be added perlite powder , cinders , sand , rice husk , sawdust , etc. to improve soil permeability water permeability . Suitable for growing grass seed to soil pH of 5.0-6.5 most , while the pH value of the local natural clay mostly high or low available lime , ash or sulfur , gypsum regulation. After KING highway slope protection in practice found Spraying actually sprayed layer thickness to reach 1.2-1.25 times the design thickness than in accordance with the design of the spray thickness control is better. This is because the rock slope portion of the matrix will result in water loss caused by the actual thickness of the substrate is less than the design thickness . Spraying technique in slope protection has become an ideal slope ecological protection technology , but in the selection of protective programs before , slope stability should be fully demonstrated , can not blindly pursue green and left engineering quality problems . For the poor stability of the slope can be applied Spraying green ecological complex processing taking bolt, then prestressed anchor and other protective methods . Conclusion With the implementation of China's sustainable development strategy , infrastructure requirements of environmental protection will further enhance the ecological protection technology Spraying the slope slope protection and residential district in highway, railway , water conservancy construction field ecological restoration in the green protection, mining and other fields of materials to be further popularized. Application of anti- sock effect gas spring means better risk-resisting , has the following advantages: wide applicability, the device technology is not ground conditions, applicable to any complex formation ; design principles of simplicity , in the form of simple and reliable , suitable for different diameters the shield ;
Processing time is short, convenient transportation ; safe, reliable, durable ; economy is high, the device can be used repeatedly . Shield Shield and out of holes in the anti-risk areas is a new technology arrives , the need to constantly optimize and improve the application process in the future . Shield technology to adapt to the technology trends in the increasingly broad shield market has great development application space. |
