The jacking material is dn2200 ductile iron pipe, with an outer diameter of 2288 and an inner diameter of 2200.
The site is generally flat.
Shanghai Songjiang West Water environment purification Co., Ltd.
The phreatic water level in Shanghai is generally about 0.3 ~ 1.5m.
Pipe jacking working well and receiving well location plan pipe jacking profile pipe jacking working well profile pipe jacking receiving well profile (open caisson) design drawing of water stop device at the beginning of pipe jacking at present, there are three types of pipe jacking heads commonly used for medium and long-distance pipe jacking: grid water flushing type, earth pressure balancing type and mud water balancing type, which have their own advantages and disadvantages: (1) grid water flushing type is a relatively old-fashioned head, which does not have the balance function without adding air pressure; It has the function of air pressure balance under the condition of adding air pressure.
In order to prevent excessive resistance during pipeline advance, thixotropic mud should be injected during construction to reduce jacking resistance.
3.3.2 confined water there are ⑥ 2 confined water and ⑦ 1 and ⑦ 2 confined water in the exploration depth of the proposed site.
If the spoil is milled and mixed into mud, the equipment is complex and it is not easy to grind evenly..
The landform of the site belongs to zone Ⅰ 1 of the lake marsh plain.
The interface adopts xtj socket type.
The proposed site is mainly open space in the plant area and newly acquired open space, and part of it is farmland.
phase III reconstruction and expansion project management department directory 1 Overview of pipe jacking project 12.
4.
Project Name: Shanghai Songjiang West water environment purification Co., Ltd.
3.3 groundwater 3.3.1 the shallow groundwater in the diving site belongs to phreatic water.
It uses the plastic, fluid and water tight soil in the soil tank to produce a certain pressure to balance the groundwater pressure and earth pressure, and uses the screw conveyor to discharge the soil.
phase III reconstruction and expansion project plan name: dn2200 pipe jacking special construction plan prepared by: Fu Kewen reviewed by: Guo Yanpeng reviewed by: Zhang Ming prepared on: March 15, 2021 prepared by: Shanghai Construction Fourth Construction Group Co., Ltd.
Its advantages are that it can adapt to a wide range of soil, shallow overburden, low labor intensity, good safety performance, and the discharged soil does not need to be treated.
Overview of engineering geology and hydrology 14.
It belongs to the alluvial plain of the Yangtze River Delta.
(2) Earth pressure balance type is a kind of latest pipe jacking machine.
3.2 in the surrounding environment of the site, the pipe jacking working well is located in the current farmland, without underground pipelines, and there are no surrounding buildings and structures that need to be protected.
The pipe jacking passes through Dongsheng port, which is about 2.5~3 meters deep and 5~7 meters wide, without navigation requirements.
During this survey, the measured buried depth of the stable groundwater level of each drilling hole is between 0.62 ~ 1.13m (corresponding to the Wusong elevation of +1.96 ~ +3.15m).
His advantage is that it is more convenient to remove obstacles.
The length of each section is 6 meters, and each pipe is 21307kg.
Prepared according to the unified standard for construction quality of construction engineering gb50300-2013 code for acceptance of construction quality of building foundation engineering gb50205-2018 code for design of pipe structures of water supply and drainage engineering gb50332-2017 technical specification for pipe jacking of water supply and drainage pipeline engineering cecs246-2008 code for construction and acceptance of water supply and drainage pipeline engineering gb50268-20083, engineering geology Hydrological overview 3.1 landform of the site Shanghai is located on the coast of the East China Sea and at the estuary of the Yangtze River.
Overview of pipe jacking works the tailrace discharge pipe of the project crosses the river course of Dongsheng port, with a width of about 7 meters and a depth of about 2.5 meters, In order not to affect the flood discharge of the river during construction, the pipe jacking method is adopted to pass through the river, and the pipe jacking length is 56m.
The disadvantage is that in the case of long-distance jacking, its jacking speed is restricted by the dumping mode, which leads to low efficiency, and generally has no crushing function.
Pipe jacking construction 4.1 comparison and selection of jacking equipment the project has the following characteristics: from the perspective of hydrogeological conditions, most of the pipe jacking sections are distributed in the muddy clay layer, and the groundwater level is high; From the jacking length, the one-time jacking distance of the pipeline is 56m; From the perspective of environment, the construction site is relatively open, and there are no residential houses around, but it is necessary to cross the river, and the soil covering thickness through Dongsheng port is 4.5 meters.
His shortcomings are high labor intensity, inflexible correction, low work efficiency, poor safety performance, and the discharged mud cannot be circulated, which has a great impact on the environment.
The working well of the project is located in the current farmland, and there are no buildings and structures that need to be protected around.
The ③ 1st layer has low strength and small jacking resistance.
Compilation basis 13.
If the soil is transported by sand pump, the distance is not long.
Pipe jacking construction 34.1 comparison and selection of jacking equipment 34.7 pipe jacking equipment configuration and construction technology 114.8 mud replacement 124.9 measurement and correction 124.13 construction methods such as ventilation, power supply and communication settings for long-distance pipe jacking 174.14 measures to control ground uplift and settlement 184.15 lifting and hoisting 194.16 safeguard measures for engineering difficulties 225 Risk control of key parts 255.1 risk control objective 255.2 ventilation in underground pipe jacking 255.3 protective measures near the wellhead 255.4 steel ladders up and down the working shaft 255.5 evaluation system for the operation team 255.6 acceptance of safety facilities at the construction site 265.7 flood prevention and typhoon prevention 265.8 safety of electricity for pipe jacking construction 261.
The main supply sources are atmospheric precipitation and surface runoff, and the discharge method is mainly evaporation.
2.
3.4 analysis of environmental factors the maximum buried depth of the pipe jacking works of the project is about 7.0m, and the soil layer involved in the buried depth range (less than 7.0m) is: ③ 1, ③ 2-1.
The groundwater contained in the ③ 2 ‐ 1 and ③ 2 ‐ 2 layers is mainly phreatic water, and there is a thicker ③ 1 layer above the ③ 2 ‐ 1 and ③ 2 ‐ 2 layers in some sites, so the groundwater contained is in a slightly pressurized state.
