Simple terms and common sense that subgrade engineering should understand

2.0. 1 control survey is used to establish survey control network. Include plane control survey, elevation control survey and three-dimensional control survey. 2.0.2 highway GPS control survey ihghway adopts global positioning system 2.0.3 river-crossing leveling leveling leveling leveling leveling with the line of sight exceeding the specified length across the river (or lakes, wide ditches, depressions, valleys, etc.). ) .2.0.4 Construction Survey Before and during the construction of the construction survey project, the survey and setting-out operations such as restoring the road centerline and determining the position of the structures shall be carried out on site according to the design drawings. 2.0.5 Completion Measurement After the final measurement project is completed, the actually completed project shall be comprehensively measured to prepare the completion document. 2.0.6 Cofferdam is a temporary water retaining facility for underwater construction. 2.0.7 The temporary structure of the double-walled steel cofferdam that anchors the ship's cable or is tied in the water. 2.0.8 The annular curtain wall is used to cut off the water source, reduce the leakage and prevent quicksand, sudden surge, piping and corrosion. A circle of waterproof curtain is set outside the foundation pit sideline. 2.0.9 Foundation soil is a stratum directly affected by structural load. 2.0. 10 Strengthening the foundation Strengthening the subsoil The treated foundation is strengthened by soil replacement, tamping and stabilization with organic or inorganic binder. 2.0. 1 1 Natural petroleum foundation without reinforcement or disturbance. 2.0. 12 column members made of pile-penetrating steel, wood, reinforced concrete, etc. , by hammering, vibration, water injection, static pressure, etc. 2.0. 13 penetration When the penetration hammer sinks into the pile, the pile penetration per hammer or per minute should be calculated according to the type of hammer, and measured in millimeters/blow and millimeters/minute. 2.0. 14 Cast-in-place concrete pile is a pile formed by manually or mechanically drilling holes in the foundation and pouring concrete into the holes. 2.0. 15 large-diameter piles This specification defines bored piles with a diameter greater than or equal to 2.5m as large-diameter piles. 2.0. 16PHP Mud Acrylamide Mud, namely PHP Mud, is a non-dispersive, low-solid and high-viscosity mud which is prepared by the hydrolysate of bentonite, sodium carbonate and polyacrylamide and sawdust, straw, cement or organic fiber composite in a certain proportion. 2.0. 17 Friction piles Friction piles mainly rely on the friction between the pile surface and the foundation to support the load. 2.0. 18 bearing piles The bearing piles mainly rely on the reaction force at the bottom of the pile to support the load. 2.0. 19 open caisson foundation, hollow shaft structure with blade feet on top and bottom, sunk to the design elevation, and built the foundation with the shaft as the structural shell. 2.0.20 Diaphragm Wall Diaphragm Wall adopts special groove (hole) forming equipment, excavates a groove (or hole) with a certain width (or diameter) and depth along the periphery of deep foundation or underground structure, sets a reinforcing cage in the groove (or hole), and pours concrete with conduit method to form unit wall (or pile) sections, which are constructed in turn. Connected into a continuous underground reinforced concrete wall in a certain way, it is used as the foundation for seepage prevention, retaining soil and supporting adjacent buildings, and directly becomes a part of the foundation structure bearing vertical load during foundation pit excavation. This kind of underground wall is the cast-in-place reinforced concrete diaphragm wall. 2.0.2 1 guide wall is used to guide the construction of underground continuous wall, accumulate mud and maintain the surface height, support the mechanical equipment for wall excavation, maintain the stability of the topsoil at the top of the trench and prevent surface water from flowing in plate, zigzag and inverted L-shaped structures. 2.0.22 Flash butt welding of steel bars is a pressure welding method, in which two steel bars are put into the butt joint, and the metal at the contact point is melted by resistance heat, resulting in strong splash and flash, which is quickly completed by adding upsetting force. 2.0.23 Steel bar electroslag pressure welding is a pressure welding method in which steel bars are placed in the form of vertical butt joint, and welding current passes through the gap between the end faces of two steel bars, forming arc process and electroslag process under the flux layer, generating arc heat and resistance heat, melting steel bars and pressurizing them. 2.0.24 Submerged arc pressure welding of embedded steel bars is a pressure welding method that steel bars and steel plates are placed in the form of T-shaped connection, and the welding current is used to generate an arc under the flux layer to form a molten pool, which is completed by pressure. 2.0.25 Mechanical connection of steel bars is a connection method that transfers the force in one steel bar to another steel bar through the mechanical bite of the connector or the bearing effect of the end face of the steel bar. 2.0.26 Extrusion sleeve joint Extrusion sleeve joint is a joint formed by connecting the plastic deformation of steel sleeve and tightly meshing ribbed steel bars through extrusion force. 2.0.27 Tapered thread sleeve joint Tapered thread sleeve joint is a joint formed by the engagement of special tapered thread at the end of steel bar with tapered sleeve. 2.0.28 Straight thread sleeve joint Straight thread sleeve joint is a joint formed by the engagement of special straight thread at the end of steel bar and straight thread sleeve. 2.0.29 The welding mesh is a steel mesh formed by vertically arranging longitudinal and transverse steel bars with the same or different diameters at a certain distance, and all intersections are welded together by resistance welding. 2.0.30 cement strength cement strength is expressed by strength grade, and the compressive strength and flexural strength at specified age are divided in Mpa, and the cement strength grades are 32.5, 32.5R, 42.5, 42.5R, 52.5R, 62.5R and 62.5 r in turn. 2.0.3 1 durability of concrete under normal design, construction, use and maintenance conditions, concrete has the ability of frost resistance, steel corrosion resistance and impermeability within the designed service life. 2.0.32 Mass Concrete Mass concrete is called mass concrete when the minimum side length of mass concrete is 1 ~ 3m and measures must be taken to avoid the temperature difference caused by hydration heat exceeding 25℃. 2.0.33 Pre-tensioning method is a construction method in which pre-stressed steel bars are tensioned on the pedestal first, and then cement concrete is poured to form pre-stressed concrete members. 2.0.34 Post-tensioning method Post-tensioning method is a construction method in which cement concrete is poured first, and prestressed tendons are tensioned after the specified strength is reached to form prestressed concrete members. 2.0.35 Rubble meets the engineering requirements, and stones with irregular shape and side length generally not less than 15cm are obtained through excavation and selection. 2.0.36 Stones that meet the engineering requirements are roughly square stones that have been mined and processed. 2.0.37 The trimmed stone is the stone with regular shape cut and processed according to the specified requirements. 2.0.38 The surface coefficient of a structure refers to the ratio of the cooling area (m2) of the structure to the volume (m3) of the structure. 2.0.39 Step-by-step method (step-by-step operation) is a construction method in which the supports and templates that can move longitudinally on the pier are assembled on it step by step or cast-in-place cement concrete beams are applied and prestressed step by step. 2.0.40 Cast-in-place cantilever casting method is a construction method in which working platforms are set on both sides of the pier, and the cement concrete beam is cantilever-cast to the middle of the span in a balanced way, and prestressed step by step. 2.0.4 1 hanging basket mobile suspended scaffold is used to bear the construction load and the beam's self-weight when cantilever pouring cement concrete beams such as cable-stayed bridges, T-beams and continuous beams, and the specially designed main process equipment can be moved forward section by section. The main components are bearing system, lifting system, anchoring system, walking system, formwork and supporting system. 2.0.42 expansion joints preset gaps in the building to reduce the influence of material expansion on the building. 2.0.43 Settlement joint preset gap in the building to reduce the influence of uneven deformation of foundation on the building. 2.0.44 During the construction of construction joint concrete, it is impossible to continuously pour at one time due to technical or construction organization reasons, but the overlapping surface or spacer groove of post-cast strip shall be reserved at the designated position of the structure. 2.0.45 Cantilever assembly method is a construction method that suspenders are arranged on both sides of the pier, precast cement concrete beams are cantilever-assembled to the mid-span section by section in a balanced way, and prestress is applied section by section. 2.0.46 bracket bracket bracket pier top beam section and nearby beam section construction, casting suspension part, using pier and steel embedded parts or universal bar bracket. 2.0.47 Scaffolding temporary support cantilever casting construction pier top beam section and nearby beam section, according to the pier height, bearing platform type and terrain conditions, steel or universal bar support is adopted to support on the pier top and bearing platform respectively. 2.0.48 box girder datum section is the first beam block to control the bridge axis and elevation in cantilever assembly construction. During prefabrication, axis and elevation control marks are embedded in the top surface of this beam block, which requires high dimensional accuracy and is placed on the pier side during cantilever assembly. 2.0.49 Prestressed concrete beams bonded with epoxy resin are prefabricated in blocks, cantilever assembled into long-span continuous beams, and the beams are connected into an integral joint with cast-in-place concrete. 2.0.5 1 incremental launching method, incremental launching method is a construction method of pouring or assembling the beam section by section at the bridge head, installing a guide beam at the front end of the beam body, and pushing the beam body longitudinally with a jack, so that the beam body passes through the temporary sliding support at the top of each pier. 2.0.52 During the lifting construction of skateboard (PTEE), a temporary pad is inserted into the lifting slide between the main girder and the pier slide or guide device, and the temporary pad consists of a steel plate sandwiched with rubber and pasted with a PTFE plate. 2.0.53 Pre-camber Pre-camber is a correction amount reserved in the opposite direction of displacement in order to offset the displacement (deflection) of beams, arches, trusses and other structures under load during construction or manufacturing. 2.0.54 Construction Load Temporary load considered in the construction stage to check the safety of bridge structures or components, such as structural gravity, construction equipment, crowds, wind, one-way thrust of arch bridge, etc. 2.0.55 ring (layer) segmental pouring method Conclusion When pouring long-span arch ring (arch rib) on arch frame, in order to reduce the load of arch frame, it is divided into several banners along the longitudinal direction of arch ring or poured in layers up and down. When dividing the banners, the middle banner should be poured and closed first, and then other banners should be poured in stages with lateral symmetry, and the pouring order should be determined by calculation. 2.0.56 Multi-worksite method is used for layered and balanced pouring of concrete for long-span skeleton concrete arch ring (arch rib). The arch ring is divided into several working faces in the longitudinal direction, and each working face is divided into several working sections in the transverse direction, and each working face is poured in a balanced way. 2.0.57 Cable-stayed concrete arch ring (arch rib) is poured by cable-stayed system. When the arch ring (arch rib) is poured by cable-stayed system, the buckling point is selected at the appropriate position of the arch rib, and the steel strand is used as the buckling cable (stay cable) to connect the temporary towers arranged on both sides. In the process of concrete pouring, the buckle cable is tensioned or relaxed according to the stress of each segment. 2.0.58 Cable-stayed stability system of wind cable system is a temporary device specially designed for fixing arch ribs, including wind cable and its auxiliary facilities, so as to realize unsupported lifting of arch ribs and ensure lateral stability of arch ribs. 2.0.59 Cable hoisting method The construction method of transporting and installing bridge members on cable towers with cable support for cableway erection. 2.0.60 Swing Bridge Swing Method The construction method of prefabricating two half-hole bridge span structures by river bank topography, and turning in place on the pier or abutment to close the span. 2.0.6 1 the smallest unit of a part or component, such as joint plate, flange, etc. 2.0.62 Component is a unit composed of several parts, such as welded H-beam and bracket. 2.0.63 Component unit is the basic unit of steel structure composed of components or parts, such as beams, columns and supports. 2.0.64 A set of high-strength bolts and their matching nuts and washers. 2.0.65 Sliding coefficient In high-strength bolt connection, the ratio of the external force when the friction surface of the connector slides to the sum of the pre-tightening force of the high-strength nut perpendicular to the friction surface. 2.0.66 Ultrasonic flaw detection Ultrasonic flaw detection is a method to detect the quality of structure or steel welding by using ultrasonic waves. 2.0.67 X-ray flaw detection γ or X-ray flaw detection is a method to check the quality of structure or steel welding by using X-rays and γ-rays. 2.0.68 Pre-assembly test assembly is used to test whether the components meet the installation quality requirements. 2.0.69 Ambient temperature 2.0.70 Anchorage generally refers to the anchorage system of the main cable. Comprise an anchor block, a saddle and other auxiliary structures. 2.0.7 1 cable tower cable bent tower supports the tower structure of the main cable of suspension bridge or cable-stayed bridge. 2.0.72 The construction catwalk is a construction access road for the construction needs of cable strand erection, cable tightening, cable clamp installation, sling erection, stiffening beam erection and steel wire winding of suspension bridges. 2.0.73 The cable saddle is a saddle-shaped supporting device arranged at the top of the tower of the suspension bridge. 2.0.74 Cable clamp is a clip-on component that connects the suspension cable and the main cable. 2.0.75 The suspender is a tension member connecting the main cable and the main girder of a suspension bridge. Transfer the dead load and live load borne by the main girder to the main cable. 2.0.76 Stiffened steel box girder is a steel box component that supports the bridge deck and makes it integrated with the bridge deck, and transmits the dead load and live load to the pylon through cranes and cables or to the pier through the beam bottom support. 2.0.77 The main cable of the stay cable bears tension and is the main supporting component of the main girder. 2.0.78 Initial Tension Tension applied to the cable when it is installed. 2.0.79 Adjust the cable force to improve the internal force and deformation of the section of the main girder and pylon. 2.0.80 The expansion body of modular expansion equipment (joint) is an expansion device composed of special-shaped steel beams and unit rubber sealing belts. It is suitable for highway bridge engineering with expansion and contraction of 80 ~ 1200mm. 2.0.8 1 expansion equipment filled with elastic-plastic materials (joints) The expansion body is made of high-viscosity elastic-plastic materials and crushed stones and filled in the expansion joints, which is called the expansion equipment filled with elastic-plastic materials. Suitable for medium and small span highway bridge engineering with expansion less than 50 mm 2.0.82 The expansion equipment (joint) for filling composite modified asphalt expansion body is made of composite modified asphalt and crushed stone and filled in the expansion joint, which is called composite modified asphalt filling expansion device. 2.0.83 Jacking method, which is suitable for small and medium-span highway bridge engineering with expansion less than 50 mm, is a construction method that uses jacking equipment to jack prefabricated box-shaped or round-tube structures into subgrade step by step to form interchange passages or culverts. 2.0.84 Temporary structure bearing the reaction of jack during jacking construction of bridge and culvert.