【正文】 he basis of minimum cost and technical advantages structures in particular are exposed for all to produce a structure that is visually offensive ,as has occurred all too often in the past, is an act professional for major spans ,but also for more ordinary structures ,architectural advice should be sought early in conceptual stage of the design process.第二篇：橋梁混凝土結(jié)構(gòu)耐久性施工方案《橋梁混凝土結(jié)構(gòu)耐久性施工方案》一、編制說明根據(jù)施工設(shè)計圖提供技術(shù)參數(shù)及資料，本工程地處多為鹽堿和鹽堿水環(huán)境，其地質(zhì)多為海相沉積形成，富含ClSO2等多種離子。壓帶是橋運輸跨越萊茵河的一個管道和人行道，跨徑446英尺。想象的工程學(xué)藉著許多特別的技術(shù)示范已經(jīng)延長混凝土建筑的范圍，就橋梁而言，已經(jīng)遠(yuǎn)遠(yuǎn)超過幾年以前可以想象的到的任何事。另一方面，橋梁有一種向大跨徑發(fā)展的明顯趨勢。在板被安置之后，這樣的梁經(jīng)常在預(yù)澆梁的先張拉 與合成梁的后張拉后結(jié)合。對于公路，用瀝青鋪設(shè)的表面可以直接用在預(yù)制混凝土的上面。采用預(yù)制、現(xiàn)場澆筑或兩種方法并用。對于服務(wù)于其它目的步行街和橋梁的設(shè)計要求由當(dāng)?shù)氐幕虻胤降拇a建立。對于一個標(biāo)準(zhǔn)HS20的公路，空心板適合于大約50 英尺的跨徑。完成的沃爾特迪斯尼樂園單軌鐵路的一系列的特征, 每個包括六個單獨支持的預(yù)拉梁，一起形成連續(xù)結(jié)構(gòu)。對于跨河橋，因為航行間隙的需求，中間可能不可以搭設(shè)橋墩。預(yù)應(yīng)力混凝土橋梁很適合于大跨徑的另一種形式是懸索箱梁。討論橋梁形式應(yīng)適當(dāng)?shù)目紤]結(jié)構(gòu)的美學(xué)。二、根據(jù)混凝土防腐設(shè)計設(shè)計圖依據(jù)工程施工規(guī)范標(biāo)準(zhǔn)：《普通混凝土配合比設(shè)計規(guī)程》JGJ552011）《公路工程混凝土結(jié)構(gòu)防腐技術(shù)規(guī)范》（JIC/TB07012006）《混凝土結(jié)構(gòu)工程施工質(zhì)量驗收規(guī)范》(GB502042015)《混凝土耐久性檢驗評定標(biāo)準(zhǔn)》(JGJ/T1932009)《混凝土外加劑》（BG87062008）《天津市鋼筋混凝土耐久性設(shè)計規(guī)程》（DB/291652006）《天津市市政工程施工技術(shù)規(guī)范》（DB2975JI0406）《混凝土結(jié)構(gòu)工程施工質(zhì)量驗收規(guī)范》（GB502042015）《普通混凝土拌合物性能試驗方法標(biāo)準(zhǔn)》（GB/500802016）《普通混凝土長期性能和耐久性能試驗方法標(biāo)準(zhǔn)》（GB/T50082016）1《普通混凝土拌合物力學(xué)試驗方法標(biāo)準(zhǔn)》（GB/T50082016）1《用于水泥和混凝土中的?；郀t礦渣》（BG/T180462008）1《用于水泥和混凝土中的粉煤灰》（BG/T15962005）1《混凝土拌合水標(biāo)準(zhǔn)》（JGJ632006）1《公路工程質(zhì)量檢驗評定標(biāo)準(zhǔn)》（JTGF80/12018）1《公路橋涵施工技術(shù)規(guī)范》（JTG/F502011）三、防腐混凝土耐久性配合比選擇：充分考慮混凝土配合比試配時的指標(biāo)：電通量、抗凍性、抗裂性、密實性、耐磨性、耐蝕性、抗堿骨料反應(yīng)檢驗滿足工程要求。選生產(chǎn)廠家反擊破生產(chǎn)碎石方式，并且要三級配選生產(chǎn)（），各個粒徑標(biāo)示并分倉清楚、壓碎值不大于10%、級配良好、含泥量、泥塊含量、針片狀等技術(shù)指標(biāo)滿足規(guī)范要求。、碎石含水量試驗根據(jù)試驗室理論配合比換算成施工配合比，質(zhì)量負(fù)責(zé)人負(fù)責(zé)核對，并交給攪拌機操作員輸入程序中。①每個工班至少2組，樁基直徑深度大于20米3組深度每超過10米增加1組。七、混凝土耐久性質(zhì)量試驗及檢驗驗證，試件尺寸為100*100*,凍融循環(huán)試驗以相對彈性模量下降至75%或重量損失率達5%時，即可認(rèn)為試件已達破壞，該試驗凍融循環(huán)次數(shù)為抗凍融等級。 controls necessary for operating the taximeter as well as four readout first channel will give the sum of money required from the first passenger, while the second and third readouts are for the second and third passengers, fourth readout will give the total ine of the contents of the last readout should be nonvolatile and be able to be retained even during parking the channel rotary selector switchs 1 , 2 and 3 have fully clockwise/anticlockwise the fully anticlockwise position, the counter of the corresponding readout is blancked and the fully clockwise position, the counter is unblanked, cleared to zero and enabled to be ready for counting the sum of money required from the first, second and third passengers, the total sum pushbutton 4 unblanks the fourth readout enabling any person to retain the readout corresponding to the total the release of the pushbutton, the fourth readout will be blanked unit also contains the main electronic circuit which will be fully described in the following OF THE MAIN ELECTRONIC CIRCUIT The general block diagram of the main electronic circuit is shown in Figure consists of five subcircuits designated by the symboles CTI up to CT4supporting circuits, these are: The number of passenger deticition circuit CTI, travelling distance scaling circuit CT2, waiting time scaling circuit CT3, circuit CT4 which generates clock pulses for the display of Passengers Detection Circuit CT1 As shown from the general block diagram, the circuit CTI has three inputs I, 2 and 3 as well as three outputs J, K and function of the circuit is to supply a high level voltage at terminals J, K or L if and only if one, two or three passengers are hiring the taxicab, term passenger, here, means one person or a group of related a passenger is getting into the cab, we simply turn on a free readout display by turning the corresponding rotary selector switch to a fully clockwise will automatically disconnect the corresponding terminal I, 2 or 3 from logical relation between various input terminals I, 2 and 3 and the output terminals J, K and L is shown in Table a binational circuit we start the design by deriving a set of boolean possible simplified boolean functions that gives minimum number of inputs to gates may be obtained from Table possible logical diagram that is based on the above derived expressions is shown in Figure consists of two inverters, four 2input AND, to3input AND two 3input OR gates Distance Scaling Circuit CT2 As shown from the block diagram of Figure 4, the circuit CT2 has four input J, K, L and E and one output function of the circuit is to supply a single pulse at the output M for a certain number of pulses generated at the output of the speed sensor(certain number of meters travelled by the taxicab), according to the number of passengers hiring the suggested fare per kilometer of travelling distance is shown in colomn two of Table circuit, in this case, should supply a single pulse at the output M for every 100, 125 or 143 pulses generated at the input terminal E according to the level of voltage at input terminale 3, K or L, circuit could be, as shown in Figure 5, three decade counters, connected as a three digit frequency divider whose dividing ratios 100, 125 and 143 are automatically selected by the voltage level at terminals J, K and L, possible circuit diagram that may verify the above function is shown in Figure consists of three decade counters type 7490, one BCDto decimal decoder type 7445, three 4input AND, one 3input ANDone 2input AND two 3input OR Scaling Circuit CT3 As shown in the block diagram, the time scalingcircuit will have four inputs J, K, L and F and one output function of this circuit and accordingto colomn three of Table 2(fare per 2 minuts of waiting time)is to supply a single pulse at the output N for every 120, 240 or 360 pulses supplied at the input terminal F from the I Hz clock according to level of voltage at inputs J, K and L, scaling circuit would be similar to the distance scaling circuit but with different diving Possible circuit diagram is shown in figure consists, in this case, of three decade counter type 7490, two 3input AND, one 5input AND, one 2input AND one 3input OR CT4 Which Genera