46results about How to "Excavation face stability" patented technology

The invention relates to an earth pressure balance shield foaming agent and a preparation technology thereof. The earth pressure balance shield foaming agent is prepared from 4-15% by weight of sodium dodecyl sulfate, 1-10% by weight of cetyltrimethylammonium chloride, 2-8% by weight of cocamidopropyl betaine, 1-5% by weight of dodecyldimethylamine oxide, 0.1-0.5% by weight of disodium ethylene diamine tetraacetate, 0.1-2.0% by weight of a tackifier and the balance water. The earth pressure balance shield foaming agent has a simple formula and high effects, and utilizes cetyltrimethylammonium chloride with excellent permeability, flexibility, emulsification effects and sterilization performances as a cationic surfactant which can be mixed with other surfactants. The earth pressure balance shield foaming agent is environmentally friendly, has excellent permeability and lubricity and can effectively improve excavated soil fluidity and watertightness.

The invention relates to an annular pipe jacking machine which comprises an annular shell, a cutter head, a muddy water system, a synchronous grouting system, a jacking mechanism, a guide system and a control system. The annular shell comprises an outer-layer shell body and an inner-layer shell body, the cutter head is arranged in the annular shell, the muddy water system comprises a mud inlet and outlet pipeline and a mud and water separation treatment device, the mud and water separation treatment device is arranged on the ground, grouting pipes of the synchronous grouting system are arranged in the annular shell and sections of a jacking pipe respectively, thixotropic slurry is injected through a grouting hole, the jacking mechanism is arranged in a jacking pipe work well and used for jacking the sections of the jacking pipe, the guide system comprises a gyroscope, a tilt meter and a height gauge which are used for determining the posture of the annular pipe jacking machine and tunneling precision, and the control system is arranged on the ground and used for performing cooperative control on the cutter head, the muddy water system, the synchronous grouting system, the jacking mechanism and the guide system. Compared with the prior art, an excavated section is small, the shape of the section is flexible, and the annular pipe jacking machine is suitable for building tunnels with large sections and extra-large sections.

The underground excavation construction method of large-span subway stations in hard rock formations can effectively reduce the risk of excavation construction and improve the efficiency of excavation construction. The method comprises the following steps: excavating the middle of the arch of the station by two steps, first excavating the upper step in the middle of the arch of the tunnel, and applying the initial support arch cover; excavating the lower step in the middle of the arch of the tunnel; excavating the upper step of the tunnel arch On the left side of the tunnel arch and on the right side of the tunnel arch, lock-foot anchors are installed at the arch foot, and the initial support arch cover of the long vault is connected to complete the construction of the initial support arch cover; The rock mass at the lower part of the station is divided into three parts: left, middle and right, and three steps of upper, middle and lower. A total of 9 parts are excavated, and the corresponding section of the side wall is initially supported until the end of the excavation; The main structure of the station has been completed.

The invention belongs to the technical field of civil engineering construction, and in particular relates to a method and device for excavating foundation pits by sinking piles, the purpose of which is to provide an earthwork honeycomb array excavation method for foundation pits, which reduces earthwork barging and on-site earthwork piles The field occupies. In this method, the excavation array of the foundation pit is firstly divided into regions to form several partitioned soil layers, and type I soil-borrowing tool pipes are driven into the boundary to form boundaries; Excavation, after the excavation of the first layer of soil is completed, excavate the soil of the second layer of soil, and repeat until the remaining soil area is left; finally, insert the type II soil extraction tool tube, and move the soil extraction tools in sequence Pipe, complete the excavation of foundation pit earthwork. The device is a soil-borrowing tool tube, including a hollow tube body and a one-way check mechanism at the bottom. The one-way check mechanism includes two soil retaining plates spliced ​​and connected, and the sides of the two soil retaining plates that are close to each other are respectively hinged with the positioning rod Connection, also includes three limit bar.

The invention relates to the technical field of mechanical control of building construction and mainly discloses an automatic control device and an automatic control method for the head-earth pressure in mechanical tube jacking construction. The automatic control device comprises a tube jacking machine, a front shell, hydraulic oil cylinders, a rear shell, a sealing device, a jacking-in tube section, an overflow valve, a hydraulic pump station, a hydraulic pipeline and a hydraulic oil loop, and is characterized in that the tube jacking machine is arranged at the front end of jacking-in direction in the mechanical jacking, the front shell and the rear shell are arranged at the rear part of the tube jacking machine, and are connected by a plurality of hydraulic oil cylinders, sealing devices are arranged outside the hydraulic oil cylinders, the plurality of hydraulic oil cylinders are respectively connected in parallel by the hydraulic pipeline and are respectively connected with the hydraulic pump station, and the hydraulic pump station is provided with the hydraulic oil loop which is provided with the overflow valve. The automatic control device disclosed by the invention can respond to the head-on earth pressure of the tube jacking machine in real time, then the control device automatically adjusts the jacking force of a head of the tube jacking machine, the control oil supply can be realized by the adjustable overflow valve on an oil path, so that the tube jacking machine can respond to the pressure of the head-on earth pressure in real time, the effect of earth pressure balance is realized, and the method is simple and effective.

The invention provides a construction method for improving shield soil in a composite sand gravel stratum. Water, foam and bentonite slurry are used as composite improvement additives; and different additives are selectively injected to the front of a cutter head, the inside of a soil barn or a screw conveyor according to the actual working condition during shield driving with the aid of special improvement equipment and processes so as to play a role in improving the plastic fluidity of the soil, reducing the torque of the cutter head, stabilizing the excavation face and improving the driving efficiency.

The invention relates to an improved construction method of a soil mass of an extra-large-diameter soil pressure balancing shield on a soft soil stratum, which particularly solves the construction travelling problem of the extra-large-diameter soil pressure balancing shield. The improved construction method of the soil mass of the extra-large-diameter soil pressure balancing shield on the soft soil stratum comprises the following steps: adopting foam and bentonite slurry as additives in the tunneling construction process, injecting the additives to different positions of an excavation surfaceof a cutter, focusing on the foam and controlling the stability of soil pressure, causing bentonite slurry to play a subsidiary role and reducing the excavation strength of the soil mass, simultaneously adopting a central agitator in a soil warehouse to agitate and mix the soil mass and the additives entering into the soil warehouse and further stabilizing the excavation surface, improving the plastic fluidity, reducing the torque of the cutter and improving the tunneling efficiency.

A water-rich sand layer shield tunneling slag improvement construction test method includes the following steps: 1. Adding prefabricated modifiers to the shield machine cutter head, soil bin and screw conveyor respectively. 2. Determine the modifier parameters: Select the first 100m of the shield as the test section, set the same excavation parameters, and set different modifier parameters, and test the excavation in the test section. 3. Measure the parameters of the tunnel, the amount of unearthed soil and the improvement parameters of the slag after the excavation, and adjust the parameters of the modifier to determine the parameters of the modifier during the formal excavation. 4. Determine the excavation parameters: the parameters of the modifier are the same, and the shield machine will try to excavate in the test section under different excavation parameters. 5. Measure the tunnel parameters, excavation volume and slag improvement parameters after excavation and adjust the excavation parameters to determine the formal excavation parameters of the shield machine. The method solves the problem that in the prior art, due to the unreasonable setting of the modifier parameters and the tunneling parameters, the slag soil improvement effect is not good, the tunneling speed is reduced, and the wear of the shield machine is increased.