Liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway
Technical field
The utility model relates to the ground-roadbed structure of high-speed railway, particularly a kind of seismic hardening structure that is used for high-speed railway liquefied soil foundation-roadbed.
Background technology
China is vast in territory, and saturated silt, saturated sand, saturated silty sand soil, loess distribution are in extensive range, and this earthen foundation very easily liquefies under geological process, causes foundation failure, and the safety of structure is thereon built in harm.The a large amount of sand silt foundation of coastal areas such as East China distribution, Xuzhou Area as Beijing-Shanghai High-Speed Railway process along the line then is saturated silty sand Tu Qu, most of area, North China, northwest then is the loess distribution district, secondary terrace groundwater table wherein is higher, have saturated loess in a big way, such as the Zheng Xi Line for Passenger Transportation the secondary terrace, the Weihe River of process be exactly typical saturated loess zone.
Build high-speed railway in these areas, just must consider the problem of liquefied soil foundation roadbed seismic hardening.It is the main reason that high-speed railway takes place by destruction that the liquefaction of liquefied soil foundation, lateral flow and embankment destroy caused Embankment Subsidence, on the basis of improving the antiseismic liquefaction destruction of existing ground reinforcing technique, take into full account geology, the soil condition of high-speed railway, the Seismic Design Method of setting up liquefied soil foundation-embankment structure is extremely important.
The China Express Railway building size is big, circuit is long, the circuit of quite a few is through liquefaction soil district and high intensity Zone, press for a kind of practicable liquified soil foundation-bed shock-resistant strengthening method and ground-roadbed earthquake resistant structure form, this new form of structure should possess that construction technology is simple, cost rationally and condition such as compliance with environmental protection requirements.
The utility model content
Technical problem to be solved in the utility model provides a kind of liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway, has intensity height, rigidity is big, seismic stability is good characteristics.
The technical scheme that its technical problem that solves the utility model adopts is: liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway of the present utility model, it is characterized in that it comprises: reinforce stake, in ground longitudinally, the lateral separation arranges that its end passes the foundation liquefaction soil layer and gos deep into non-liquefaction soil layers; Cement graded broken stone reinforcement cushion is layed between ground basal plane and the reinforcing stake stake top; Reinforced soil embankment is layed on the cement graded broken stone reinforcement cushion.
As the further optimization to technique scheme, described reinforcing stake also is included at least two row's fender piles that the outer both sides of reinforced soil embankment toe add cloth; Each is reinforced the stake stake and holds the degree of depth of going deep into non-liquefaction soil layers to be not less than 1.0m, and the stake footpath is 0.5~0.8m, and pile spacing is 3~5 times of stake footpaths.
The beneficial effects of the utility model are, combine the characteristics separately of stake-cement graded broken stone reinforcement cushion structure and reinforced soil embankment, stake-cement graded broken stone reinforcement cushion-native three's acting in conjunction, upper load is more reasonably transmitted and be allocated in the stake and inter-pile soil on; Cement graded broken stone reinforcement cushion has improved intensity, rigidity, horizontal restraint power, the water isolating of bed course, prevents the mattress layer failure phenomenon, can more effectively upper load be transmitted in the stake during earthquake, improves the whole seismic stability of roadbed ground simultaneously; Reinforced soil embankment has improved the horizontal restrain power and the whole seismic stability of roadbed body.A whole set of scheme makes stake-cement graded broken stone reinforcement cushion structure foundation and roadbed body be coupled to an interactional organic whole, the compatibility of deformation of ground when having increased earthquake-cement graded broken stone reinforcement cushion-roadbed has improved the whole anti-seismic performance of ground roadbed greatly.
Description of drawings
This manual comprises following four width of cloth accompanying drawings:
Fig. 1 is vertical sectional schematic diagram of the utility model liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway;
Fig. 2 is vertical sectional schematic diagram of cement graded broken stone reinforcement cushion in the utility model liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway;
Fig. 3 is the schematic diagram of reinforced soil embankment in the utility model liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway.
Fig. 4 is the graded broken stone grading curve figure of cement graded broken stone reinforcement cushion in the utility model liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway.
Toponym shown in the figure and pairing mark: reinforced soil embankment 10, first floor roadbed filling 11a, second layer roadbed filling 11b, the 3rd layer of roadbed filling 11c, the 4th layer of roadbed filling 11d, the unidirectional high-strength geo-grid 12a of first floor, the unidirectional high-strength geo-grid 12b of the second layer, the 3rd layer of unidirectional high-strength geo-grid 12c, unidirectional low strong geo-grid 13, cement graded broken stone reinforcement cushion 20, first floor cement graded broken stone 21a, second layer cement graded broken stone 21b, the 3rd layer of cement grating stone 21c, the two-way high-strength geo-grid 22a of first floor, the two-way high-strength geo-grid 22b of the second layer, reinforce stake 30, fender pile 30a.
The specific embodiment
Below in conjunction with drawings and Examples the utility model is further specified.
With reference to Fig. 1, liquified soil foundation-bed shock-resistant strengthening structure of high-speed railway of the present utility model comprises: reinforce stake 30, in ground longitudinally, the lateral separation arranges that its end passes the foundation liquefaction soil layer and gos deep into non-liquefaction soil layers; Cement graded broken stone reinforcement cushion 20 is layed between ground basal plane and 30 tops of reinforcing stake; Reinforced soil embankment 10 is layed on the cement graded broken stone reinforcement cushion 20.Combine the characteristics separately of a web frame and reinforced soil embankment, stake-cement graded broken stone reinforcement cushion-native three's acting in conjunction, upper load is more reasonably transmitted and be allocated in the stake and inter-pile soil on; Cement graded broken stone reinforcement cushion 20 has improved intensity, rigidity, horizontal restraint power, the water isolating of bed course, prevents the mattress layer failure phenomenon, can more effectively upper load be transmitted in the stake during earthquake, improves the whole seismic stability of roadbed ground simultaneously; Reinforced soil embankment 10 has improved the horizontal restrain power and the whole seismic stability of roadbed body.A whole set of scheme makes stake-cement graded broken stone reinforcement cushion structure foundation and roadbed body be coupled to an interactional organic whole, the compatibility of deformation of ground when having increased earthquake-cement graded broken stone reinforcement cushion-roadbed has improved the whole anti-seismic performance of ground roadbed greatly.
Described reinforcing stake 30 can be adopted rigid pile such as semi-rigid stake such as cement mixing pile, CFG (CFG stake) or reinforced concrete pile.Reinforce the laying of stake 30 in the ground except that satisfying bearing capacity, sedimentation and deformation, stability requirement, also to satisfy the requirement of seismic design, the degree of depth that 30 ends of each reinforcing stake go deep into non-liquefaction soil layers is not less than 1.0m, and the stake footpath is 0.5~0.8m, and pile spacing is 3~5 times of stake footpaths.With reference to Fig. 1, for further improving the shock resistance of ground-roadbed, described reinforcing stake 30 also is included at least two row's fender pile 30a that the outer both sides of reinforced soil embankment 10 toes add cloth.
With reference to Fig. 2, the thickness of described cement graded broken stone reinforcement cushion 20 is 60~80cm, is made of the cement graded broken stone filler of compacting and vertical within it two-way high-strength geo-grid of laying at interval.The volume of Portland cement is 4~6% of a graded broken stone weight in the cement graded broken stone filler, and coefficient of consolidation is not less than 0.95, and void content is not more than 28%.Cement graded broken stone filler can play the effect of following two aspects: 1. strengthen the cohesion between the grating gravel particle, the lateral displacement of restriction bed course, improve the rigidity of bed course, prevent under the geological process because of the lost efficacy bed course graded broken stone that causes that sink of inter-pile soil bearing capacity falls, make cement graded broken stone reinforcement cushion 20 can continue to keep its load and share ability with compatible deformation; 2. increase the water isolating of graded broken stone reinforcement cushion 20, stop ground pore water rising infiltration roadbed body under the geological process, effectively prevent the destruction of caving in that the roadbed non-deformability descends and causes.Thereby improved the rigidity and the resistance to overturning of graded broken stone bed course, thus upper load is transmitted in the stake when more effectively guaranteeing earthquake, improved the whole seismic stability of roadbed simultaneously.The compound that each graded broken stone is made of by a certain percentage thickness rubble and aggregate chips, should meet closely knit grating requirement, generally form through broken, screening by cut into a mountain stone or natural pebble, gravel, it is good that the grain composition of graded broken stone is wanted, and the match ratio grain composition of compound need satisfy requirement shown in Figure 4.Two-way high-strength geo-grid is along the horizontal elongated laying of liquefied soil foundation, and its ultimate tensile strength is greater than 100kN/m, and the nominal strength elongation per unit length is not more than 10%, mesh size 80~150mm.The cement graded broken stone reinforcement cushion of being made up of good cement graded broken stone of grating and two-way high-strength geo-grid 20 is transition regions that top reinforced soil embankment 10 and bottom reinforce stake 30, play and adjust native vertical load share ratio of stake and stress ratio effect, bear load jointly and reduce sedimentation thereby make stake-cement graded broken stone reinforcement cushion-soil form organic whole.Simultaneously, add 4~6% ordinary Portland cement and two-way high-strength geo-grid in the graded broken stone, intensity, rigidity, horizontal restraint power, the water isolating of bed course have been improved, prevent the mattress layer failure phenomenon, in the time of more effectively guaranteeing earthquake upper load is transmitted in the stake, improves the whole seismic stability of roadbed ground.
Shown in Figure 2 is a kind of Typical Disposition structure of cement graded broken stone reinforcement cushion 20, and promptly cement graded broken stone reinforcement cushion 20 is made of first floor cement graded broken stone 21a, the two-way high-strength geo-grid 22a of first floor, second layer cement graded broken stone 21b, the two-way high-strength geo-grid 22b of the second layer and the 3rd layer of cement graded broken stone 21c of laying successively from top to bottom; The thickness of first floor cement graded broken stone 21a, second layer cement graded broken stone 21b and the 3rd layer of cement graded broken stone 21c all is not less than 100mm.After laying first floor cement graded broken stone 21a above the reinforcing stake 30, re-lay the two-way high-strength geo-grid 22a of first floor, can avoid the dissection of a top edge limitedly geo-grid.
With reference to Fig. 3, described reinforced soil embankment 10 is by the roadbed filling of compacting and vertical within it unidirectional high-strength geo-grid of laying at interval, and vertical unidirectional low strong geo-grid 13 of laying at interval constitutes between the unidirectional high-strength geo-grid of adjacent two layers, the adding of geogrids layer, retrained the lateral deformation of subgrade soils, improve the strength and stiffness of roadbed body, strengthened the resistance to overturning of roadbed.Unidirectional high-strength geo-grid is along the horizontal elongated laying of roadbed, and its ultimate tensile strength requires greater than 100kN/m, and the nominal strength elongation per unit length is not more than 10%, mesh size 80~150mm.Unidirectional low strong geo-grid 13 is layed in the side slope 1.2~1.6m scope of both sides, and its ultimate tensile strength requires 40~60kN/m, and the nominal strength elongation per unit length is not more than 10%, mesh size 60~160mm.
Shown in Figure 3 is a kind of Typical Disposition structure of reinforced soil embankment 10, be that reinforced soil embankment 10 comprises the first floor roadbed filling 11a that lays successively from top to bottom, the unidirectional high-strength geo-grid 12a of first floor, second layer roadbed filling 11b, the unidirectional high-strength geo-grid 12b of the second layer, the 3rd layer of roadbed filling 11c, the 3rd layer of unidirectional high-strength geo-grid 12c and the 4th layer of roadbed filling 11d, up lay successively by this rule, until the roadbed end face, and the unidirectional low strong geo-grid 13 of vertical laying at interval between the unidirectional high-strength geo-grid of adjacent two layers, between each unidirectional low strong geo-grid 13, vertical 30cm at interval between unidirectional low strong geo-grid 13 and the high-strength geo-grid of adjacent one-way.
Roadbed filling and compacting criteria such as following table 1-3.
The compacting criteria on table 1 reinforced earth subgrade bed top layer
Table 2 reinforced earth subgrade bed underfilling and compacting criteria
Following filler of table 3 reinforced earth subgrade bed and compacting criteria